content/common/features.cc

// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/common/features.h"

#include "base/feature.h"
#include "base/feature_list.h"
#include "base/metrics/field_trial_params.h"
#include "base/time/time.h"
#include "third_party/blink/public/common/features.h"

namespace features {

// Please keep features in alphabetical order.

#if BUILDFLAG(IS_ANDROID)
// When enabled, fires CONTENT_CHANGE_TYPE_CONTENT_INVALID events to Android
// when aria-invalid is true.
// TODO(crbug.com/500812737): Remove killswitch after stability period.
BASE_FEATURE(kAccessibilityAriaInvalidAndErrorMessage,
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_ANDROID)

// When enabled, Android events will include more metadata about the incoming
// events.
BASE_FEATURE(kAccessibilityExpandEventMetadata,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, the full accessibility tree will be exposed for non-atomic
// text fields, such as contenteditables.
BASE_FEATURE(kAccessibilityExposeNonAtomicTextFieldChildren,
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enables content-initiated, main frame navigations to data URLs.
// TODO(meacer): Remove when the deprecation is complete.
//               https://www.chromestatus.com/feature/5669602927312896
BASE_FEATURE(kAllowContentInitiatedDataUrlNavigations,
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enables forwarding WebKeyboardEvent of type kKeyDown from confirmed physical
// keyboards to KeyPressEventCallback listeners in RenderWidgetHostImpl on
// Android.
// Owner: lkuba@google.com, piotrkotynia@google.com
// Removal: Check after 2026-11-01
BASE_FEATURE(kAllowKeyDownInKeyPressListeners,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, AncestorThrottle evaluates redirect responses using the source
// URL of the redirect rather than the target URL.
BASE_FEATURE(kAncestorThrottleEvaluateRedirectSource,
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enables desktop-style scrollbars.
BASE_FEATURE(kAndroidDesktopStyleScrollbars, base::FEATURE_ENABLED_BY_DEFAULT);

// Allows Blink to request fonts from the Android Downloadable Fonts API through
// the service implemented on the Java side.
BASE_FEATURE(kAndroidDownloadableFontsMatching,
             base::FEATURE_ENABLED_BY_DEFAULT);

#if BUILDFLAG(IS_WIN)
// Flag guard for Windows Arabic Indic digit input solution.
// crbug.com/440381284
BASE_FEATURE(kArabicIndicDigitInput, base::FEATURE_ENABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_WIN)

// If enabled, runs beforeunload handlers asynchronously when the user
// hasn't interacted with the frame. (See: https://crbug.com/475716933)
BASE_FEATURE(kAsyncBeforeUnload, base::FEATURE_DISABLED_BY_DEFAULT);

BASE_FEATURE_PARAM(base::TimeDelta,
                   kAsyncBeforeUnloadTimeout,
                   &kAsyncBeforeUnload,
                   "AsyncBeforeUnloadTimeout",
                   base::Milliseconds(500));

// Synchronously continuing with navigation can lead to trying to start another
// navigation synchronously while the first navigation is still being processed
// on the stack. This results in re-entrancy which is unsafe and triggers a
// CHECK.
//
// Embedders like Android WebView cannot guarantee that re-entrancy would never
// occur - in particular, there are existing Android WebView apps that do the
// problematic sync navigation. Hence Android WebView entirely disables this
// feature via
// ContentBrowserClient::SupportsAvoidUnnecessaryBeforeUnloadCheckSync().
//
// The eventual goal of this feature flag is to make it possible to continue
// navigation synchronously for some platforms
// (See: https://crbug.com/396998476).
//
// There are several modes that are described in the
// AvoidUnnecessaryBeforeUnloadCheckSyncMode enum in the header file.
//
// The eventual state is to utilize kWithoutSendBeforeUnload mode, as it offers
// the highest performance. However, kWithoutSendBeforeUnload mode causes a
// metrics skew due to the current inaccurate measurement timing of navigation
// start (refer to crbug.com/385170155). Therefore, kWithSendBeforeUnload mode
// is the current default. We would like to update to use
// kWithoutSendBeforeUnload mode once crbug.com/385170155 is resolved.
BASE_FEATURE(kAvoidUnnecessaryBeforeUnloadCheckSync,
             base::FEATURE_ENABLED_BY_DEFAULT);

constexpr base::FeatureParam<AvoidUnnecessaryBeforeUnloadCheckSyncMode>::Option
    kAvoidUnnecessaryBeforeUnloadCheckSyncModeOption[] = {
        {AvoidUnnecessaryBeforeUnloadCheckSyncMode::kWithSendBeforeUnload,
         "WithSendBeforeUnload"},
        {AvoidUnnecessaryBeforeUnloadCheckSyncMode::kWithoutSendBeforeUnload,
         "WithoutSendBeforeUnload"},
};

BASE_FEATURE_ENUM_PARAM(
    AvoidUnnecessaryBeforeUnloadCheckSyncMode,
    kAvoidUnnecessaryBeforeUnloadCheckSyncMode,
    &kAvoidUnnecessaryBeforeUnloadCheckSync,
    AvoidUnnecessaryBeforeUnloadCheckSyncMode::kWithSendBeforeUnload,
    &kAvoidUnnecessaryBeforeUnloadCheckSyncModeOption);

// Enables controlling the time to live for pages in the BackForwardCache.
// The time to live is defined by the param 'time_to_live_seconds'; if this
// param is not specified then this feature is ignored and the default is used.
BASE_FEATURE(kBackForwardCacheTimeToLiveControl,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, the browser will schedule before unload tasks that continue
// navigation network responses in a kHigh priority queue.
// TODO(b/281094330): Run experiment on ChromeOS. Experiment was not run on
// ChromeOS due to try bot issue.
BASE_FEATURE(kBeforeUnloadBrowserResponseQueue,
#if BUILDFLAG(IS_CHROMEOS)
             base::FEATURE_DISABLED_BY_DEFAULT
#else
             base::FEATURE_ENABLED_BY_DEFAULT
#endif
);

#if BUILDFLAG(IS_ANDROID)
// Whether to hide paste popup on GestureScrollBegin or GestureScrollUpdate.
BASE_FEATURE(kHidePastePopupOnGSB, base::FEATURE_ENABLED_BY_DEFAULT);
#endif

#if BUILDFLAG(IS_MAC)
// If true, whenever the cache lookup falls back to the selection, allow the
// fallback even if the requested range is outside the selection. If the
// selection is invalid, returns an empty result.
BASE_FEATURE(kCachedFirstRectAllowRangeOutsideSelection,
             base::FEATURE_ENABLED_BY_DEFAULT);

BASE_FEATURE(kCancelCompositionWhenWindowLosesFocus,
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_MAC)

// When enabled, CDP method Page.captureScreenshot will increment
// the LocalSurfaceId instead of waiting for ForceRedraw to complete.
// This should avoid a possible stall due to frames not being presented.
BASE_FEATURE(kCDPScreenshotNewSurface, base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, code cache does not use a browsing_data filter for deletions.
BASE_FEATURE(kCodeCacheDeletionWithoutFilter, base::FEATURE_ENABLED_BY_DEFAULT);

// Turn on a bug fix for crbug.com/456537756, ensuring that the callback passed
// to RenderWidgetHostView::CopyFromSurface() is always called.
BASE_FEATURE(kCopyFromSurfaceAlwaysCallCallback,
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enables support for the `Critical-CH` response header.
// https://github.com/WICG/client-hints-infrastructure/blob/master/reliability.md#critical-ch
BASE_FEATURE(kCriticalClientHint, base::FEATURE_ENABLED_BY_DEFAULT);

#if BUILDFLAG(USE_ZYGOTE)
// When enabled, the browser does not wait for the sandboxed zygote to finish
// booting (and report its sandbox status) during early startup; the handshake
// completes when the zygote is first needed instead. When disabled it is
// completed on the main thread right after the FeatureList is available,
// before BrowserMain.
BASE_FEATURE(kDeferZygoteHandshake, base::FEATURE_DISABLED_BY_DEFAULT);
#endif

// This feature controls whether Dev Tools supports debugging Device Bound
// Sessions.
BASE_FEATURE(kDeviceBoundSessionsDevTools, base::FEATURE_ENABLED_BY_DEFAULT);

// This feature enables the fix for double releases of
// WorkerOrWorkletDevToolsAgentHost to prevent UAF.
BASE_FEATURE(kWorkerOrWorkletAgentDoubleReleaseFix,
             base::FEATURE_ENABLED_BY_DEFAULT);

// This feature gates the entry to ServiceWorkerDevToolsAgentHost to ensure
// it is only accessible when DevTools is actually attached.
BASE_FEATURE(kServiceWorkerDevToolsWorkerReadyCheck,
             base::FEATURE_ENABLED_BY_DEFAULT);

// This feature gates the entry to SharedWorkerDevToolsAgentHost to ensure
// it is only accessible when DevTools is actually attached.
BASE_FEATURE(kSharedWorkerDevToolsWorkerReadyCheck,
             base::FEATURE_ENABLED_BY_DEFAULT);

#if BUILDFLAG(IS_ANDROID)
// Disables the auto_resize_output_surface feature in the Viz process.
// This prevents visual artifacts (blue gutters) during window resizing on
// large form factor devices.
BASE_FEATURE(kDisableAutoResizeOutputSurface, base::FEATURE_ENABLED_BY_DEFAULT);
#endif

// Enable DocumentIsolationPolicy even if the platform does not support full
// SiteIsolation.
BASE_FEATURE(kDocumentIsolationPolicyWithoutSiteIsolation,
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enable document policy negotiation mechanism.
BASE_FEATURE(kDocumentPolicyNegotiation, base::FEATURE_DISABLED_BY_DEFAULT);

#if BUILDFLAG(IS_ANDROID)
// When enabled, sandboxed renderer processes (except spare renderers) are
// initially bound with a strong (BIND_IMPORTANT) binding right at creation
// time, putting them immediately in the top-app cpuset group on Android.
BASE_FEATURE(kEarlyTopAppForSandboxedRenderer,
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif

// When enabled `EditContext::updateSelection` calls from async selectionchange
// handlers sync the selection to the browser.
// See https://crbug.com/516839844
BASE_FEATURE(kEditContextSelectionSync, base::FEATURE_ENABLED_BY_DEFAULT);

// When enabled, the renderer is killed if a renderer process provides
// an Origin header on a navigation request.
BASE_FEATURE(kKillOnUnexpectedOriginHeader, base::FEATURE_ENABLED_BY_DEFAULT);

// Requires documents embedded via <iframe>, etc, to explicitly opt-into the
// embedding: https://github.com/mikewest/embedding-requires-opt-in.
BASE_FEATURE(kEmbeddingRequiresOptIn, base::FEATURE_DISABLED_BY_DEFAULT);

// Enables error reporting for JS errors inside DevTools frontend host
#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
BASE_FEATURE(kEnableDevToolsJsErrorReporting,
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)

// When enabled, the browser process will terminate a renderer process if it
// attempts to bind gamepad Mojo interfaces (GamepadMonitor or
// GamepadHapticsManager) when the "gamepad" Permissions Policy is blocked.
BASE_FEATURE(kEnforceGamepadPermissionsPolicy,
             base::FEATURE_ENABLED_BY_DEFAULT);

// When enabled, enforces that same-document navigations must not change
// the committed origin, insecure request policy, or insecure navigations set.
// Any mismatch will result in a renderer kill via bad_message handling.
//
// This defends against renderer misbehavior and session history corruption,
// and helps catch violations of same-document invariants.
//
// This feature acts as a kill switch for https://crbug.com/40580002.
//
// Note: This feature remains disabled if
// blink::features::kTreatMhtmlInitialDocumentLoadsAsCrossDocument is disabled.
BASE_FEATURE(kEnforceSameDocumentOriginInvariants,
             base::FEATURE_DISABLED_BY_DEFAULT);

// Content counterpart of ExperimentalContentSecurityPolicyFeatures in
// third_party/blink/renderer/platform/runtime_enabled_features.json5. Enables
// experimental Content Security Policy features ('navigate-to').
BASE_FEATURE(kExperimentalContentSecurityPolicyFeatures,
             base::FEATURE_DISABLED_BY_DEFAULT);

// Controls whether FedCM preserves ports in well-known URLs during testing.
// When enabled, well-known URLs retain the original port from the provider URL
// instead of stripping it via eTLD+1 extraction. This is primarily used in
// test environments where IdPs run on non-standard ports (e.g., localhost:8080)
// and the well-known endpoint needs to be fetched from the same port.
// Production FedCM strips ports for security reasons to ensure well-known
// files are served from the canonical domain.
BASE_FEATURE(kFedCmPreservePortsForTesting, base::FEATURE_DISABLED_BY_DEFAULT);

// Enables installed web app matching for getInstalledRelatedApps API.
BASE_FEATURE(kFilterInstalledAppsWebAppMatching,
             base::FEATURE_ENABLED_BY_DEFAULT);
#if BUILDFLAG(IS_WIN)
// Enables installed windows app matching for getInstalledRelatedApps API.
// Note: This is enabled by default as a kill switch, since the functionality
// was already implemented but without a related feature flag.
BASE_FEATURE(kFilterInstalledAppsWinMatching, base::FEATURE_ENABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_WIN)

#if BUILDFLAG(IS_ANDROID)
// This is a kill switch for focusing the RenderWidgetHostViewAndroid on
// MouseDown if not focused already, please see crbug.com/515000108. The root
// view, RWHVA, is always focused for main tabs in Chrome, however this might
// not be true for WebContents hosted outside of tabs (such as WebView or
// ThinWebView). Unlike ActionDown focus, this is not disabled on WebView.
BASE_FEATURE(kFocusRenderWidgetHostViewAndroidOnMouseDown,
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif
// This feature controls whether the renderer should use FontDataManager to
// fetch fonts from the Browser's FontDataService. It is currently scoped to
// Linux and ChromeOS. See
// crbug.com/335680565.
#if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
const base::FeatureParam<FontDataServiceTypefaceType>::Option
    font_data_service_typeface[] = {
        {FontDataServiceTypefaceType::kFreetype, "Freetype"},
        {FontDataServiceTypefaceType::kFontations, "Fontations"}};
#if BUILDFLAG(IS_LINUX)
BASE_FEATURE(kFontDataServiceLinux, base::FEATURE_ENABLED_BY_DEFAULT);
BASE_FEATURE_ENUM_PARAM(FontDataServiceTypefaceType,
                        kFontDataServiceTypefaceType,
                        &kFontDataServiceLinux,
                        "typeface",
                        FontDataServiceTypefaceType::kFontations,
                        &font_data_service_typeface);
#else
BASE_FEATURE(kFontDataServiceChromeOS, base::FEATURE_DISABLED_BY_DEFAULT);
BASE_FEATURE_ENUM_PARAM(FontDataServiceTypefaceType,
                        kFontDataServiceTypefaceType,
                        &kFontDataServiceChromeOS,
                        "typeface",
                        FontDataServiceTypefaceType::kFontations,
                        &font_data_service_typeface);
#endif  // BUILDFLAG(IS_LINUX)
#endif  // BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)

// Enables speculative font family prewarming through FontDataManager.
BASE_FEATURE(kFontDataManagerPrewarming, base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, route CSS local() font lookups through FontDataService.
BASE_FEATURE(kFontDataServiceForCSSLocalFonts,
             base::FEATURE_DISABLED_BY_DEFAULT);

#if BUILDFLAG(IS_WIN) || BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_CHROMEOS)
bool IsFontDataServiceEnabled() {
#if BUILDFLAG(IS_WIN)
  return true;
#elif BUILDFLAG(IS_LINUX)
  return base::FeatureList::IsEnabled(features::kFontDataServiceLinux);
#elif BUILDFLAG(IS_CHROMEOS)
  return base::FeatureList::IsEnabled(features::kFontDataServiceChromeOS);
#else
  return false;
#endif
}
#endif

// Whether to use the Frame Routing Cache to avoid synchronous IPCs from the
// renderer side for iframe creation.
BASE_FEATURE(kFrameRoutingCache, base::FEATURE_ENABLED_BY_DEFAULT);
const base::FeatureParam<int> kFrameRoutingCacheResponseSize{
    &kFrameRoutingCache, "responseSize", 4};

// Guards the lifetime mediation fix for the Geolocation active frame count.
// When enabled, `GeolocationProxy` is introduced in the browser process to
// intermediate between the renderer and the Device Service's Geolocation
// implementation. This ensures the active frame count (UI location indicator)
// is tied to the actual geolocation data pipe lifetime, rather than just the
// broker connection.
// When disabled, legacy pass-through binding is used.
// See crbug.com/514489361.
BASE_FEATURE(kGeolocationProxy, base::FEATURE_ENABLED_BY_DEFAULT);

// Group network isolation key(NIK) by storage interest group joining origin to
// improve privacy and performance -- IGs of the same joining origin can reuse
// sockets, so we don't need to renegotiate those connections.
BASE_FEATURE(kGroupNIKByJoiningOrigin, base::FEATURE_DISABLED_BY_DEFAULT);

// A feature to experiment with removing the soft process limit. See
// https://crbug.com/369342694.
BASE_FEATURE(kRemoveRendererProcessLimit, base::FEATURE_ENABLED_BY_DEFAULT);

// Purge PartitionAlloc's Scheduler-Loop quarantine when the UI thread is done
// executing a task. This allow purging memory without scanning the stack. See:
// https://crbug.com/329027914
BASE_FEATURE(
    kPartitionAllocSchedulerLoopQuarantineTaskObserverForBrowserUIThread,
    base::FEATURE_ENABLED_BY_DEFAULT);

// Killswitch for prefetch devtools UA override (crbug.com/422193319).
BASE_FEATURE(kPrefetchDevtoolsUserAgentOverride,
             base::FEATURE_ENABLED_BY_DEFAULT);

// When true, duplicate navigations are ignored only if they are initiated
// with a user gesture.
BASE_FEATURE(kIgnoreDuplicateNavsOnlyWithUserGesture,
             base::FEATURE_DISABLED_BY_DEFAULT);

// A feature flag for the memory-backed code cache.
BASE_FEATURE(kInMemoryCodeCache, base::FEATURE_DISABLED_BY_DEFAULT);

// Enables the ability to use the updateIfOlderThanMs field in the trusted
// bidding response to trigger a post-auction update if the group has been
// updated more recently than updateIfOlderThanMs milliseconds, bypassing the
// typical 24 hour wait.
BASE_FEATURE(kInterestGroupUpdateIfOlderThan, base::FEATURE_ENABLED_BY_DEFAULT);

// Enable IOSurface based screen capturer.
#if BUILDFLAG(IS_MAC)
BASE_FEATURE(kIOSurfaceCapturer, base::FEATURE_ENABLED_BY_DEFAULT);
#endif

// When enabled, holds back (disables) the early-return optimization in
// SiteInstanceImpl::IsSuitableForUrlInfo.
BASE_FEATURE(kIsSuitableForUrlInfoEarlyReturnHoldback,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, child process will not terminate itself when IPC is reset.
BASE_FEATURE(kKeepChildProcessAfterIPCReset, base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, the renderer process will be killed if it provides
// invalid (non-allowlisted) headers in a navigation request.
BASE_FEATURE(kKillOnInvalidNavigationHeaders, base::FEATURE_ENABLED_BY_DEFAULT);

// Kill switch for crbug.com/424995036. When enabled, the top of a
// PopupWidgetHost is constrained to be at or below the line of death.
BASE_FEATURE(kLimitPopupWidgetHostPosition, base::FEATURE_ENABLED_BY_DEFAULT);

// Enables Local Network Access checks for all types of web workers.
//
// The exact checks run are the same as for other document subresources, and
// depends on the state of the main Local Network Access feature flags
//`kLocalNetworkAccessChecks`.
BASE_FEATURE(kLocalNetworkAccessForWorkers, base::FEATURE_ENABLED_BY_DEFAULT);

// Enables Local Network Access checks in warning mode for all types of web
// workers.
//
// Does nothing if `kLocalNetworkAccessForWorkers` is disabled.
//
// If both this and `kLocalNetworkAccessChecksForWorkers` are enabled, then LNA
// requests for workers do not require a permission, but simply display a
// warning in DevTools.
BASE_FEATURE(kLocalNetworkAccessForWorkersWarningOnly,
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enables Local Network Access checks for main frame navigations.
//
// The exact checks run are the same as for other document subresources, and
// depends on the state of the main Local Network Access feature flags
//`kLocalNetworkAccessChecks`.
BASE_FEATURE(kLocalNetworkAccessForNavigations,
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enables Local Network Access checks in warning mode for main frame
// navigations.
//
// Does nothing if `kLocalNetworkAccessForNavigations` is disabled.
//
// If both this and `kLocalNetworkAccessChecksForNavigations` are enabled, then
// main frame navigations that qualify as LNA requests do not require a
// permission, but simply display a warning in DevTools.
BASE_FEATURE(kLocalNetworkAccessForNavigationsWarningOnly,
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enables Local Network Access checks for subframe navigations.
//
// The exact checks run are the same as for other document subresources, and
// depends on the state of the main Local Network Access feature flags
//`kLocalNetworkAccessChecks`.
BASE_FEATURE(kLocalNetworkAccessForSubframeNavigations,
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enables Local Network Access checks in warning mode for subframe navigations.
//
// Does nothing if `kLocalNetworkAccessForSubframeNavigations` is disabled.
//
// If both this and `kLocalNetworkAccessChecksForSubframeNavigations` are
// enabled, then subframe navigations that qualify as LNA requests do not
// require a permission, but simply display a warning in DevTools.
BASE_FEATURE(kLocalNetworkAccessForSubframeNavigationsWarningOnly,
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enables Local Network Access checks for subframe navigations.
//
// The same checks are run as for other document subresources, and depends on
// the state of the main Local Network Access feature flags
//`kLocalNetworkAccessChecks`, however when enabled these navigations are
// blocked without triggering a permission prompt.
//
// See crbug.com/409303581 for more discussion of Fenced Frames and LNA.
BASE_FEATURE(kLocalNetworkAccessForFencedFrameNavigations,
             base::FEATURE_ENABLED_BY_DEFAULT);

// Enables Local Network Access checks in warning mode for fenced frame
// navigations.
//
// Does nothing if `kLocalNetworkAccessForFencedFrameNavigations`
// is disabled.
//
// If both this and `kLocalNetworkAccessChecksForFencedFrameNavigations` are
// enabled, then fenced frame navigations that qualify as LNA requests are not
// blocked, but simply display a warning in DevTools.
BASE_FEATURE(kLocalNetworkAccessForFencedFrameNavigationsWarningOnly,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, allows the ReusePrerenderingProcessForMainFrames feature
// and the ProcessPerSiteUpToMainFrameThreshold feature to reuse processes
// even when DevTools was ever attached.
// This allows developers to test the process sharing mode,
// since DevTools normally disables it for the field trial participants.
BASE_FEATURE(kMainFrameProcessReuseAllowDevToolsAttached,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, allows the ReusePrerenderingProcessForMainFrames feature
// and the ProcessPerSiteUpToMainFrameThreshold feature to reuse processes
// even for IP and localhost pages.
// These pages are common targets for devtools.
BASE_FEATURE(kMainFrameProcessReuseAllowIPAndLocalhost,
             base::FEATURE_DISABLED_BY_DEFAULT);

// If this feature is enabled, media-device enumerations use a cache that is
// invalidated upon notifications sent by base::SystemMonitor. If disabled, the
// cache is considered invalid on every enumeration request.
BASE_FEATURE(kMediaDevicesSystemMonitorCache,
             "MediaDevicesSystemMonitorCaching",
#if BUILDFLAG(IS_MAC) || BUILDFLAG(IS_WIN)
             base::FEATURE_ENABLED_BY_DEFAULT
#else
             base::FEATURE_DISABLED_BY_DEFAULT
#endif
);

// Allow cross-context transfer of MediaStreamTracks.
BASE_FEATURE(kMediaStreamTrackTransfer, base::FEATURE_DISABLED_BY_DEFAULT);

// If enabled Mojo uses a dedicated background thread to listen for incoming
// IPCs. Otherwise it's configured to use Content's IO thread for that purpose.
BASE_FEATURE(kMojoDedicatedThread, base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, additional spare RPHs will be warmed up when the browser is
// not busy.
BASE_FEATURE(kMultipleSpareRPHs, base::FEATURE_ENABLED_BY_DEFAULT);

BASE_FEATURE_PARAM(size_t,
                   kMultipleSpareRPHsCount,
                   &kMultipleSpareRPHs,
                   "count",
                   1u);

// When enabled, performs a dry run of the Navigation Fast Fetch feature.
// It determines eligibility of navigations and records metrics to measure
// the potential benefit of fetching document resources early, without
// actually performing the fetching.
BASE_FEATURE(kNavigationFastFetchDryRun, base::FEATURE_ENABLED_BY_DEFAULT);

// When enabled, NavigationThrottleRunner2 is used instead of the original
// NavigationThrottleRunner. See https://crbug.com/422003056.
BASE_FEATURE(kNavigationThrottleRunner2, base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, precomputes SiteInfo once in BrowsingInstance entry-points
// and passes it down to avoid redundant calculations.
BASE_FEATURE(kPrecomputeSiteInfo, base::FEATURE_DISABLED_BY_DEFAULT);

// This feature enables Permissions Policy verification in the Browser process
// in content/. Additionally only for //chrome Permissions Policy verification
// is enabled in components/permissions/permission_context_base.cc
#if !BUILDFLAG(IS_ANDROID)
BASE_FEATURE(kPermissionsPolicyVerificationInContent,
             "kPermissionsPolicyVerificationInContent",
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif  // !BUILDFLAG(IS_ANDROID)

// When enabled, OnMouseEvent uses the event's actual pointer type for
// last_pointer_type_ instead of unconditionally reporting kMouse, and skips
// updating last_pointer_type_ for synthesized mouse events so that a preceding
// pen/touch pointer type is not clobbered.
BASE_FEATURE(kMouseEventPreservePointerType, base::FEATURE_ENABLED_BY_DEFAULT);

// If enabled, responses with an operative Cookie-Indices will not be used
// if the relevant cookie values have changed.
BASE_FEATURE(kPrefetchCookieIndices, base::FEATURE_DISABLED_BY_DEFAULT);

// Preloading holdback feature disables preloading (e.g., preconnect, prefetch,
// and prerender) on all predictors. This is useful in comparing the impact of
// blink::features::kPrerender2 experiment with and without them.

// Enables extension interception for preload activation report beacons.
BASE_FEATURE(kPreloadActivationReportWithExtensionInterception,
             base::FEATURE_DISABLED_BY_DEFAULT);

// This Feature allows configuring preloading features via a parameter string.
// See content/browser/preloading/preloading_config.cc to see how to use this
// feature.
BASE_FEATURE(kPreloadingConfig, base::FEATURE_ENABLED_BY_DEFAULT);

BASE_FEATURE(kPrioritizeResizeTaskRunnerOnStartup,
             base::FEATURE_DISABLED_BY_DEFAULT);

// A misunderstanding when fixing crbug.com/40076091 meant that non-speculative
// RFHs were being created with a provisional RenderFrame in the renderer. This
// is nominally harmless, but can crash prerenders if devtool's network
// overrides feature is enabled. Guarded by a feature since fixing this new bug
// might reintroduce the previous crashes.
BASE_FEATURE(kPrerenderMoreCorrectSpeculativeRFHCreation,
             base::FEATURE_ENABLED_BY_DEFAULT);

// This feature makes it so that having pending views increase the priority of a
// RenderProcessHost even when there is a priority override.
BASE_FEATURE(kPriorityOverridePendingViews, base::FEATURE_ENABLED_BY_DEFAULT);

// Enables exposure of the core milestone 1 (M1) APIs in the renderer without an
// origin trial token: Attribution Reporting, FLEDGE, Topics.
BASE_FEATURE(kPrivacySandboxAdsAPIsM1Override,
             base::FEATURE_ENABLED_BY_DEFAULT);

#if BUILDFLAG(IS_ANDROID)
// When disabled("legacy behavior") it resets ongoing gestures when window loses
// focus. In split screen scenario this means we can't continue scroll on a
// chrome window, when we start interacting with another window.
BASE_FEATURE(kContinueGestureOnLosingFocus, base::FEATURE_DISABLED_BY_DEFAULT);
#endif

// Make sendBeacon throw for a Blob with a non simple type.
BASE_FEATURE(kSendBeaconThrowForBlobWithNonSimpleType,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, try to reuse an unlocked renderer process when COOP swap is
// happening on prerender initial navigation. Please see crbug.com/41492112 for
// more details.
BASE_FEATURE(kProcessReuseOnPrerenderCOOPSwap,
#if BUILDFLAG(IS_ANDROID)
             base::FEATURE_DISABLED_BY_DEFAULT
#else
             base::FEATURE_ENABLED_BY_DEFAULT
#endif
);

// Causes the browser to progressively disable accessibility for WebContents
// some time after they become hidden.
BASE_FEATURE(kProgressiveAccessibilityPhase2,
             base::FEATURE_DISABLED_BY_DEFAULT);

// Minimizes Mojo URLLoaderFactory cloning overhead during navigation and worker
// startup.
BASE_FEATURE(kReduceMojoURLLoaderFactoryCloning,
             base::FEATURE_DISABLED_BY_DEFAULT);

// Controls whether lazy URLLoaderFactory cloning is used for service worker
// fallback factory.
BASE_FEATURE_PARAM(bool,
                   kUseLazyURLLoaderFactoryForServiceWorkerFallback,
                   &kReduceMojoURLLoaderFactoryCloning,
                   false);

// Controls whether lazy URLLoaderFactory cloning is used for subresource
// proxying factory bundle during navigation commit.
BASE_FEATURE_PARAM(bool,
                   kUseLazyURLLoaderFactoryForSubresourceProxying,
                   &kReduceMojoURLLoaderFactoryCloning,
                   false);

// Causes hidden tabs with crashed subframes to be marked for reload, meaning
// that if a user later switches to that tab, the current page will be
// reloaded.  This will hide crashed subframes from the user at the cost of
// extra reloads.
BASE_FEATURE(kReloadHiddenTabsWithCrashedSubframes,
#if BUILDFLAG(IS_ANDROID)
             base::FEATURE_ENABLED_BY_DEFAULT
#else
             base::FEATURE_DISABLED_BY_DEFAULT
#endif
);

BASE_FEATURE(kRendererCancellationThrottleImprovements,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, allows a navigation to resume even if the renderer process for
// its speculative RFH is killed. This only works for navigations that have not
// yet received the response and picked the final RFH to commit in.
BASE_FEATURE(kResumeNavigationWithSpeculativeRFHProcessGone,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, the browser will try to swap to a new SiteInstance if there is
// an existing warm (pending, committed, or delayed shutdown) renderer process
// locked to the destination site and when the current process is an empty
// one (like the NTP) and would normally be reused for same-site navigations
// under partial site isolation.
BASE_FEATURE(kPreferWarmRendererProcess, base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, try to reuse any same-site process that is hosting
// only prerendered frames for main-frame navigations.
BASE_FEATURE(kReusePrerenderingProcessForMainFrames,
             base::FEATURE_ENABLED_BY_DEFAULT);

// Allows a reload to replace the initial navigation entry if it is
// the first navigation to commit. This fixes the case where a browser-initiated
// reload occurs before the first navigation has committed, resulting in
// discarding the pending entry and remaining on the about:blank page. See
// https://crbug.com/324117294.
BASE_FEATURE(kReplaceInitialEntryForReload, base::FEATURE_ENABLED_BY_DEFAULT);

#if BUILDFLAG(IS_ANDROID)
// If enabled, then orientation lock won't claim to work on anything but phone
// form factors.  Tablets already do unpredictable things, such as letterboxing
// vs rotating and/or (successfully) ignoring the request entirely.  Setting
// this flag turns off those use-cases which nobody should be relying on right
// now anyway; they don't work.
BASE_FEATURE(kRestrictOrientationLockToPhones,
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif

// Fix for scrolling to focused editable input fields after tapping to show the
// on-screen keyboard (crbug.com/462636368).
#if BUILDFLAG(IS_ANDROID)
BASE_FEATURE(kSandboxedProcessServiceLimitOnAndroid,
             base::FEATURE_DISABLED_BY_DEFAULT);

BASE_FEATURE(kScrollAfterOSKViewportShrinkFix,
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif

// Controls whether redirect Location headers are sanitized during navigation
// to only include the origin when cross-origin to the final URL.
// See https://crbug.com/495463654.
BASE_FEATURE(kSanitizeLocationHeadersDuringNavigation,
             base::FEATURE_ENABLED_BY_DEFAULT);

// Controls whether the final URL of a failed subframe navigation is sanitized
// when committing an error page in the initiator's process.
// See https://crbug.com/517156678.
BASE_FEATURE(kSanitizeFailedSubframeNavigationUrls,
             base::FEATURE_ENABLED_BY_DEFAULT);

// Controls whether the `original_url` contains the full URL or just the
// sanitized origin when sent to the renderer on commit.
// See https://crbug.com/495463654.
BASE_FEATURE(kSanitizeOriginalUrlDuringNavigation,
             base::FEATURE_ENABLED_BY_DEFAULT);

BASE_FEATURE(kServiceWorkerAvoidMainThreadForInitialization,
             base::FEATURE_ENABLED_BY_DEFAULT);

// The set of ServiceWorker to bypass while making navigation request.
// They are represented by a comma separated list of HEX encoded SHA256 hash of
// the ServiceWorker's scripts.
// e.g.
// 9685C8DE399237BDA6FF3AD0F281E9D522D46BB0ECFACE05E98D2B9AAE51D1EF,
// 20F0D78B280E40C0A17ABB568ACF4BDAFFB9649ADA75B0675F962B3F4FC78EA4
BASE_FEATURE(kServiceWorkerBypassFetchHandlerHashStrings,
             base::FEATURE_DISABLED_BY_DEFAULT);
const base::FeatureParam<std::string>
    kServiceWorkerBypassFetchHandlerBypassedHashStrings{
        &kServiceWorkerBypassFetchHandlerHashStrings,
        "script_checksum_to_bypass", ""};

// (crbug.com/41411856): When enabled, the srcdoc iframes are controlled by the
// same service worker that controls their parent.
BASE_FEATURE(kServiceWorkerSrcdocSupport, base::FEATURE_ENABLED_BY_DEFAULT);

// Enforce CORP check for Service Worker Static Router's cache source.
BASE_FEATURE(kServiceWorkerStaticRouterCORPCheck,
             base::FEATURE_ENABLED_BY_DEFAULT);

// crbug.com/495999481: When this is enabled, the navigation request should be
// blocked when it receives an opaque response from the service worker static
// router.
BASE_FEATURE(kServiceWorkerStaticRouterOpaqueCheck,
             base::FEATURE_ENABLED_BY_DEFAULT);

// (crbug.com/507149743): When enabled, the browser process and the renderer
// process repopulate parsed_headers if it is missing for the response from the
// static router.
BASE_FEATURE(kServiceWorkerStaticRouterParsedHeaders,
             base::FEATURE_ENABLED_BY_DEFAULT);

// (crbug.com/497302265): When enabled, the main script response fetching is
// consolidated into ServiceWorkerVersion.
BASE_FEATURE(kServiceWorkerStaticRouterConsolidateMainScriptResponse,
             base::FEATURE_ENABLED_BY_DEFAULT);

// (crbug.com/1371756): When enabled, the static routing API starts
// ServiceWorker when the routing result of a main resource request was network
// fallback.
BASE_FEATURE(kServiceWorkerStaticRouterStartServiceWorker,
             base::FEATURE_ENABLED_BY_DEFAULT);

// When enabled, the browser sends `ServiceWorkerVersion.typedRouterRules`
// instead of `routerRules` in CDP.
BASE_FEATURE(kServiceWorkerStaticRouterTypedRulesForDevTools,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, suppresses the service worker timeout when a payment handler
// window is open.
BASE_FEATURE(kServiceWorkerSuppressTimeoutWhenPaymentWindowOpen,
             base::FEATURE_ENABLED_BY_DEFAULT);

// (crbug.com/41337436): Enabled feature will have the ServiceWorker Client.url
// property be the creation URL. This means it does not reflect changes to the
// URL made by history.pushState() or similar history APIs.
// When disabled the ServiceWorker Client.url property will be the document URL
// including changes to history.pushState().
BASE_FEATURE(kServiceWorkerClientUrlIsCreationUrl,
             base::FEATURE_ENABLED_BY_DEFAULT);

// Kill switch for crbug.com/499449324.
BASE_FEATURE(kServiceWorkerOptionalTimeoutIterator,
             base::FEATURE_ENABLED_BY_DEFAULT);

// If enabled, the browser process verifies that the URL of a main script
// request matches the service worker's script URL.
// See https://crbug.com/497983180.
BASE_FEATURE(kServiceWorkerVerifyMainScriptUrl,
             base::FEATURE_DISABLED_BY_DEFAULT);

// (crbug.com/486495094): When enabled, triggers a soft update check after
// functional events complete (spec step 8) and on worker start failure
// (spec step 5), per the "Fire Functional Event" spec algorithm.
BASE_FEATURE(kServiceWorkerSoftUpdateOnFunctionalEvent,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, stricter and aligned context validation is performed for
// ServiceWorker start checks and message event dispatching.
BASE_FEATURE(kServiceWorkerStrictContextValidation,
             base::FEATURE_DISABLED_BY_DEFAULT);

// If enabled, the browser process will derive the secure context state of a
// SharedWorker connection from its own authoritative ground truth
// (PolicyContainerHost) instead of trusting the renderer-supplied parameter.
BASE_FEATURE(kSharedWorkerSecureContextDerivationFromBrowser,
             base::FEATURE_DISABLED_BY_DEFAULT);

// Enables skipping the early call to CommitPending when navigating away from a
// crashed frame.
BASE_FEATURE(kSkipEarlyCommitPendingForCrashedFrame,
             base::FEATURE_DISABLED_BY_DEFAULT);

// When enabled, skips registration of RendererCancellationThrottle and instead
// keeps navigation cancellation behavior by reusing the requester
// NavigationClient.
BASE_FEATURE(kSkipRendererCancellationThrottle,
             base::FEATURE_ENABLED_BY_DEFAULT);

#if BUILDFLAG(IS_ANDROID)
// When enabled, ensure high-rank processes are on the LRU list while app is in
// background or the effective binding state is in conflict with low rank
// processes.
BASE_FEATURE(kStrictHighRankProcessLRU, base::FEATURE_ENABLED_BY_DEFAULT);
#endif

// Allows swipe left/right from touchpad change browser navigation.
// On platforms that don't have this enabled by default, the overscroll gesture
// is handled at a different level and not through the interpretation of scroll
// events.
BASE_FEATURE(kTouchpadOverscrollHistoryNavigation,
#if BUILDFLAG(IS_CHROMEOS) || BUILDFLAG(IS_WIN) || BUILDFLAG(IS_LINUX)
             base::FEATURE_ENABLED_BY_DEFAULT
#else
             base::FEATURE_DISABLED_BY_DEFAULT
#endif
);

// Enable TrustedTypes .fromLiteral support.
BASE_FEATURE(kTrustedTypesFromLiteral, base::FEATURE_DISABLED_BY_DEFAULT);

// Optimize DirectManipulationHelper by updating its event handler when the
// window parent changes instead of tearing down and recreating the whole
// helper. This is a temporary flag to test the performance impact of the
// optimization.
#if BUILDFLAG(IS_WIN)
BASE_FEATURE(kUpdateDirectManipulationHelperOnParentChange,
             base::FEATURE_ENABLED_BY_DEFAULT);
#endif

// Validate the code signing identity of the network process before establishing
// a Mojo connection with it.
#if BUILDFLAG(IS_MAC)
BASE_FEATURE(kValidateNetworkServiceProcessIdentity,
             base::FEATURE_DISABLED_BY_DEFAULT);
#endif  // BUILDFLAG(IS_MAC)

// Pre-warm up the network process on browser startup.
#if BUILDFLAG(IS_ANDROID)
BASE_FEATURE(kWarmUpNetworkProcess, base::FEATURE_DISABLED_BY_DEFAULT);
#endif

// Enable WebAssembly dynamic tiering (only tier up hot functions).
BASE_FEATURE(kWebAssemblyDynamicTiering, base::FEATURE_ENABLED_BY_DEFAULT);

// Enables in-process resource loading for WebUI renderer processes.
BASE_FEATURE(kWebUIInProcessResourceLoading,
#if BUILDFLAG(IS_ANDROID)
             base::FEATURE_DISABLED_BY_DEFAULT
#else
             base::FEATURE_ENABLED_BY_DEFAULT
#endif
);

// Enables WebOTP calls in cross-origin iframes if allowed by Permissions
// Policy.
BASE_FEATURE(kWebOTPAssertionFeaturePolicy, base::FEATURE_DISABLED_BY_DEFAULT);

// Flag guard for fix for crbug.com/40942531.
BASE_FEATURE(kLimitCrossOriginNonActivatedPaintHolding,
             base::FEATURE_ENABLED_BY_DEFAULT);

// Please keep features in alphabetical order.

bool IsEnforceSameDocumentOriginInvariantsEnabled() {
  return base::FeatureList::IsEnabled(kEnforceSameDocumentOriginInvariants) &&
         base::FeatureList::IsEnabled(
             blink::features::kTreatMhtmlInitialDocumentLoadsAsCrossDocument);
}

}  // namespace features