chrome/browser/browser_features.cc - chromium/src - Git at Google

 // Copyright 2018 The Chromium Authors
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "chrome/browser/browser_features.h"

 #include "base/feature_list.h"
 #include "build/branding_buildflags.h"
 #include "build/build_config.h"

 #if BUILDFLAG(IS_WIN)
 #include "chrome/browser/net/system_network_context_manager.h"
 #endif

 namespace features {

 #if BUILDFLAG(IS_ANDROID)
 // Kill switch for allowing TWAs to autoplay with sound without requiring a user
 // gesture to unlock, for parity with PWAs.
 BASE_FEATURE(kAllowUnmutedAutoplayForTWA, base::FEATURE_ENABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(IS_ANDROID)

 // This is used to enable an experiment for modifying confidence cutoff of
 // prerender and preconnect for autocomplete action predictor.
 BASE_FEATURE(kAutocompleteActionPredictorConfidenceCutoff,
              base::FEATURE_DISABLED_BY_DEFAULT);

 // This is used to enable an experiment for the bookmarks tree view in the
 // side panel, providing users with a hierarchical view of their bookmarks.
 BASE_FEATURE(kBookmarksTreeView, base::FEATURE_DISABLED_BY_DEFAULT);

 // This is used as a kill switch for Bookmark triggered prerendering. See
 // crbug.com/40259793 for more details of Bookmark triggered prerendering.
 BASE_FEATURE(kBookmarkTriggerForPrerender2KillSwitch,
              base::FEATURE_DISABLED_BY_DEFAULT);

 // This flag is used for enabling BookmarkBar triggered preconnect.
 BASE_FEATURE(kBookmarkTriggerForPreconnect, base::FEATURE_DISABLED_BY_DEFAULT);

 // This flag is used for enabling BookmarkBar triggered prefetch.  See
 // crbug.com/413259638 for more details of Bookmark triggered prefetching.
 BASE_FEATURE(kBookmarkTriggerForPrefetch, base::FEATURE_DISABLED_BY_DEFAULT);

 // Enables Certificate Transparency on Desktop and Android Browser (CT is
 // disabled in Android Webview, see aw_browser_context.cc).
 // Enabling CT enforcement requires maintaining a log policy, and the ability to
 // update the list of accepted logs. Embedders who are planning to enable this
 // should first reach out to chrome-certificate-transparency@google.com.
 // On builds where CT is enabled, this flag is also used as an emergency kill
 // switch.
 BASE_FEATURE(kCertificateTransparencyAskBeforeEnabling,
 #if BUILDFLAG(GOOGLE_CHROME_BRANDING)
              base::FEATURE_ENABLED_BY_DEFAULT);
 #else
              base::FEATURE_DISABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(GOOGLE_CHROME_BRANDING)

 // Enables using network time for certificate verification. If enabled, network
 // time will be used to verify certificate validity, however certificates that
 // fail to validate with network time will fall back to the system time.
 // This has no effect if the network_time::kNetworkTimeServiceQuerying flag is
 // disabled, or the BrowserNetworkTimeQueriesEnabled policy is set to false.
 #if !BUILDFLAG(IS_CHROMEOS)
 BASE_FEATURE(kCertVerificationNetworkTime, base::FEATURE_ENABLED_BY_DEFAULT);
 #else
 BASE_FEATURE(kCertVerificationNetworkTime, base::FEATURE_DISABLED_BY_DEFAULT);
 #endif  // !BUILDFLAG(IS_CHROMEOS)

 // Killswitch that guards clearing all user data in the ProfileImpl destructor.
 BASE_FEATURE(kClearUserDataUponProfileDestruction,
              base::FEATURE_ENABLED_BY_DEFAULT);

 #if BUILDFLAG(IS_LINUX)
 // Enables usage of os_crypt_async::SecretPortalKeyProvider.  Once
 // `kSecretPortalKeyProviderUseForEncryption` is enabled, this flag cannot be
 // disabled without losing data.
 BASE_FEATURE(kDbusSecretPortal, base::FEATURE_ENABLED_BY_DEFAULT);

 // Enables usage of os_crypt_async::FreedesktopSecretKeyProvider, which is
 // compatible with the synchronous backend.
 BASE_FEATURE(kUseFreedesktopSecretKeyProvider,
              base::FEATURE_ENABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(IS_LINUX)

 // Destroy profiles when their last browser window is closed, instead of when
 // the browser exits.
 BASE_FEATURE(kDestroyProfileOnBrowserClose,
 #if BUILDFLAG(IS_LINUX) || BUILDFLAG(IS_MAC) || BUILDFLAG(IS_WIN)
              base::FEATURE_ENABLED_BY_DEFAULT);
 #else
              base::FEATURE_DISABLED_BY_DEFAULT);
 #endif

 // DestroyProfileOnBrowserClose only covers deleting regular (non-System)
 // Profiles. This flags lets us destroy the System Profile, as well.
 BASE_FEATURE(kDestroySystemProfiles, base::FEATURE_DISABLED_BY_DEFAULT);

 // Enables delaying the call to FullBrowserTransitionManager::OnProfileCreated()
 // until after BrowserContextDependencyManager::CreateBrowserContextServices()
 // in ProfileImpl::OnLocaleReady(). This change is thought to avoid creating
 // certain KeyedServices before they are properly initialized, but is flagged
 // guarded in case it causes unexpected issues.
 BASE_FEATURE(kDelayOnProfileCreatedForFullBrowserTransition,
              base::FEATURE_ENABLED_BY_DEFAULT);

 // Enables showing the email of the flex org admin that setup CBCM in the
 // management disclosures.
 BASE_FEATURE(kFlexOrgManagementDisclosure,
 #if BUILDFLAG(IS_CHROMEOS)
              base::FEATURE_DISABLED_BY_DEFAULT);
 #else
              base::FEATURE_ENABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(IS_CHROMEOS)

 // Enables the Incoming Call Notifications scenario. When created by an
 // installed origin, an incoming call notification should have increased
 // priority, colored buttons, a ringtone, and a default "close" button.
 // Otherwise, if the origin is not installed, it should behave like the default
 // notifications, but with the added "Close" button. See
 // https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/Notifications/notifications_actions_customization.md
 BASE_FEATURE(kIncomingCallNotifications,
 #if BUILDFLAG(IS_WIN)
              base::FEATURE_ENABLED_BY_DEFAULT);
 #else
              base::FEATURE_DISABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(IS_WIN)

 #if BUILDFLAG(ENABLE_EXTENSIONS)
 BASE_FEATURE(kInitialExternalExtensions, base::FEATURE_ENABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(ENABLE_EXTENSIONS)

 #if !BUILDFLAG(IS_ANDROID)
 // Adds a "Snooze" action to mute notifications during screen sharing sessions.
 BASE_FEATURE(kMuteNotificationSnoozeAction, base::FEATURE_DISABLED_BY_DEFAULT);
 #endif

 // This feature enables monitoring of first-party network requests in order to
 // find possible violations. Example: A Chrome policy is set to disabled but the
 // network request controlled by that policy is observed.
 BASE_FEATURE(kNetworkAnnotationMonitoring, base::FEATURE_ENABLED_BY_DEFAULT);

 // This flag is used for enabling New Tab Page triggered prerendering. See
 // crbug.com/1462832 for more details of New Tab Page triggered prerendering.
 BASE_FEATURE(kNewTabPageTriggerForPrerender2, base::FEATURE_ENABLED_BY_DEFAULT);

 // This flag is used for enabling New Tab Page triggered prefetch. See
 // crbug.com/421941586 for more details of New Tab Page triggered prefetching.
 BASE_FEATURE(kNewTabPageTriggerForPrefetch, base::FEATURE_DISABLED_BY_DEFAULT);

 #if BUILDFLAG(IS_ANDROID)
 // Adds an "Unsubscribe" action to web push notifications that allows stopping
 // notifications from a given origin with a single tap (with an option to undo).
 BASE_FEATURE(kNotificationOneTapUnsubscribe, base::FEATURE_ENABLED_BY_DEFAULT);
 base::FeatureParam<bool> kNotificationOneTapUnsubscribeUseServiceIntentParam{
     &kNotificationOneTapUnsubscribe, "use_service_intent", false};
 #endif

 // Enables executing the browser commands sent by the NTP promos.
 BASE_FEATURE(kPromoBrowserCommands, base::FEATURE_ENABLED_BY_DEFAULT);

 // Parameter name for the promo browser command ID provided along with
 // kPromoBrowserCommands.
 // The value of this parameter should be parsable as an unsigned integer and
 // should map to one of the browser commands specified in:
 // ui/webui/resources/js/browser_command/browser_command.mojom
 const char kBrowserCommandIdParam[] = "BrowserCommandIdParam";

 #if BUILDFLAG(IS_WIN) && BUILDFLAG(GOOGLE_CHROME_BRANDING)
 // When this feature is enabled, Chrome will register os_update_handler with
 // Omaha, to be run on OS upgrade.
 BASE_FEATURE(kRegisterOsUpdateHandlerWin, base::FEATURE_ENABLED_BY_DEFAULT);
 // When this feature is enabled, Chrome will install the
 // platform_experience_helper.
 BASE_FEATURE(kInstallPlatformExperienceHelperWin,
              base::FEATURE_DISABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(IS_WIN) && BUILDFLAG(GOOGLE_CHROME_BRANDING)

 // When this feature is enabled, the network service will restart unsandboxed if
 // a previous attempt to launch it sandboxed failed.
 BASE_FEATURE(kRestartNetworkServiceUnsandboxedForFailedLaunch,
              base::FEATURE_ENABLED_BY_DEFAULT);

 // Gates sandboxed iframe navigation toward external protocol behind any of:
 // - allow-top-navigation
 // - allow-top-navigation-to-custom-protocols
 // - allow-top-navigation-with-user-gesture (+ user gesture)
 // - allow-popups
 //
 // Motivation:
 // Developers are surprised that a sandboxed iframe can navigate and/or
 // redirect the user toward an external application.
 // General iframe navigation in sandboxed iframe are not blocked normally,
 // because they stay within the iframe. However they can be seen as a popup or
 // a top-level navigation when it leads to opening an external application. In
 // this case, it makes sense to extend the scope of sandbox flags, to block
 // malvertising.
 //
 // Implementation bug: https://crbug.com/1253379
 // I2S: https://groups.google.com/a/chromium.org/g/blink-dev/c/-t-f7I6VvOI
 //
 // Enabled in M103. Flag to be removed in M106
 BASE_FEATURE(kSandboxExternalProtocolBlocked, base::FEATURE_ENABLED_BY_DEFAULT);
 // Enabled in M100. Flag to be removed in M106
 BASE_FEATURE(kSandboxExternalProtocolBlockedWarning,
              base::FEATURE_ENABLED_BY_DEFAULT);

 #if BUILDFLAG(IS_LINUX)
 // If true, encrypt new data with the key provided by SecretPortalKeyProvider.
 // Otherwise, it will only decrypt existing data.
 BASE_FEATURE(kSecretPortalKeyProviderUseForEncryption,
              base::FEATURE_DISABLED_BY_DEFAULT);

 // If true, encrypt new data with the key provided by
 // FreedesktopSecretKeyProvider. Otherwise, it will only decrypt existing data.
 BASE_FEATURE(kUseFreedesktopSecretKeyProviderForEncryption,
              base::FEATURE_ENABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(IS_LINUX)

 // Enables migration of the network context data from `unsandboxed_data_path` to
 // `data_path`. See the explanation in network_context.mojom.
 BASE_FEATURE(kTriggerNetworkDataMigration,
 #if BUILDFLAG(IS_WIN)
              base::FEATURE_ENABLED_BY_DEFAULT
 #else
              base::FEATURE_DISABLED_BY_DEFAULT
 #endif
 );

 #if BUILDFLAG(IS_CHROMEOS)
 // If enabled, a blue border is drawn around shared tabs on ChromeOS.
 // If disabled, the blue border is not used on ChromeOS.
 //
 // Motivation:
 //  The blue border behavior used to (still does, see below) cause problems on
 //  ChromeOS - see crbug.com/1320262 (fixed). This flag is introduced as means
 //  of disabling this feature in case of possible future regressions.
 //
 // TODO(crbug.com/40198577): Remove this flag once we confirm that blue border
 // works fine on ChromeOS.
 //
 // b/279051234: We suspect the tab sharing blue border may cause a bad issue
 // on ChromeOS where a window can not be interacted at all. Disable the feature
 // on ChromeOS.
 BASE_FEATURE(kTabCaptureBlueBorderCrOS, base::FEATURE_DISABLED_BY_DEFAULT);
 #endif

 // Enables runtime detection of USB devices which provide a WebUSB landing page
 // descriptor.
 BASE_FEATURE(kWebUsbDeviceDetection, base::FEATURE_ENABLED_BY_DEFAULT);

 #if BUILDFLAG(IS_WIN)
 // Disable dynamic code using ACG. Prevents the browser process from generating
 // dynamic code or modifying executable code. See comments in
 // sandbox/win/src/security_level.h. Only available on Windows 10 RS1 (1607,
 // Build 14393) onwards.
 BASE_FEATURE(kBrowserDynamicCodeDisabled, base::FEATURE_DISABLED_BY_DEFAULT);

 // The Chrome DLL can be pre-read with ::PrefetchVirtualMemory() from the
 // browser or a child process. Pre-reading is supposed to bring the whole DLL in
 // physical memory more efficiently than a series of hard faults. However,
 // pre-reading consumes a non-trivial amount of CPU even when the DLL is already
 // in physical memory and it may not be necessary to have the full DLL in
 // physical memory (space taken by unused parts of the DLL could potentially be
 // used for more important stuff). This file has multiple features to experiment
 // with policies for pre-reading the Chrome DLL in child processes. The
 // `kPrefetchVirtualMemoryPolicy` feature defined elsewhere controls pre-reading
 // the Chrome DLL from the browser process.

 // When enabled, child processes never pre-read the Chrome DLL.
 BASE_FEATURE(kNoPreReadMainDll, base::FEATURE_DISABLED_BY_DEFAULT);

 // When enabled, child processes don't pre-read the Chrome DLL if we believe the
 // Chrome DLL is on an SSD (i.e. pre-read only on spinning disk).
 BASE_FEATURE(kNoPreReadMainDllIfSsd, base::FEATURE_ENABLED_BY_DEFAULT);

 // When enabled, the browser process suppresses pre-read in child processes
 // shortly after browser startup, where "shortly after" is dictated by the
 // feature param below. This is thought to be a productive strategy since the
 // browser process will have recently pre-read the DLL during browser
 // startup. In that case, the browser process has recently pre-read the DLL so
 // pre-reading again is thought to be counter-productive (CPU consumption for no
 // gains).
 BASE_FEATURE(kNoPreReadMainDllStartup, base::FEATURE_DISABLED_BY_DEFAULT);

 // Time after browser startup during which child processes don't pre-read the
 // Chrome DLL when `kNoPreReadMainDllStartup` is enabled.
 const base::FeatureParam<base::TimeDelta>
     kNoPreReadMainDllStartup_StartupDuration{&kNoPreReadMainDllStartup,
                                              "no-preread-dll-startup-time",
                                              base::Minutes(2)};

 // When enabled, the browser process will re-launch itself when launched with
 // an elevated linked token. The re-launched browser will use the token from
 // the Windows Shell (explorer.exe), which is typically non-elevated.
 BASE_FEATURE(kAutoDeElevate, base::FEATURE_ENABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(IS_WIN)

 #if !BUILDFLAG(IS_ANDROID)
 // This flag controls whether to perform Pak integrity check on startup to
 // report statistics for on-disk corruption.
 // Disabled on ChromeOS, as dm-verity enforces integrity and the check would
 // be redundant.
 BASE_FEATURE(kReportPakFileIntegrity,
 #if !BUILDFLAG(IS_CHROMEOS)
              base::FEATURE_ENABLED_BY_DEFAULT);
 #else
              base::FEATURE_DISABLED_BY_DEFAULT);
 #endif  // BUILDFLAG(IS_CHROMEOS)
 #endif  // BUILDFLAG(IS_ANDROID)

 // This flag enables the removal of IWAs surface captures from Chrome Tabs
 // category in getDisplayMedia() API. When disabled, IWAs surface captures
 // show both in Chrome Tabs and Windows.
 BASE_FEATURE(kRemovalOfIWAsFromTabCapture, base::FEATURE_ENABLED_BY_DEFAULT);

 }  // namespace features
	// Copyright 2018 The Chromium Authors
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "chrome/browser/browser_features.h"

	#include "base/feature_list.h"
	#include "build/branding_buildflags.h"
	#include "build/build_config.h"

	#if BUILDFLAG(IS_WIN)
	#include "chrome/browser/net/system_network_context_manager.h"
	#endif

	namespace features {

	#if BUILDFLAG(IS_ANDROID)
	// Kill switch for allowing TWAs to autoplay with sound without requiring a user
	// gesture to unlock, for parity with PWAs.
	BASE_FEATURE(kAllowUnmutedAutoplayForTWA, base::FEATURE_ENABLED_BY_DEFAULT);
	#endif // BUILDFLAG(IS_ANDROID)

	// This is used to enable an experiment for modifying confidence cutoff of
	// prerender and preconnect for autocomplete action predictor.
	BASE_FEATURE(kAutocompleteActionPredictorConfidenceCutoff,
	base::FEATURE_DISABLED_BY_DEFAULT);

	// This is used to enable an experiment for the bookmarks tree view in the
	// side panel, providing users with a hierarchical view of their bookmarks.
	BASE_FEATURE(kBookmarksTreeView, base::FEATURE_DISABLED_BY_DEFAULT);

	// This is used as a kill switch for Bookmark triggered prerendering. See
	// crbug.com/40259793 for more details of Bookmark triggered prerendering.
	BASE_FEATURE(kBookmarkTriggerForPrerender2KillSwitch,
	base::FEATURE_DISABLED_BY_DEFAULT);

	// This flag is used for enabling BookmarkBar triggered preconnect.
	BASE_FEATURE(kBookmarkTriggerForPreconnect, base::FEATURE_DISABLED_BY_DEFAULT);

	// This flag is used for enabling BookmarkBar triggered prefetch. See
	// crbug.com/413259638 for more details of Bookmark triggered prefetching.
	BASE_FEATURE(kBookmarkTriggerForPrefetch, base::FEATURE_DISABLED_BY_DEFAULT);

	// Enables Certificate Transparency on Desktop and Android Browser (CT is
	// disabled in Android Webview, see aw_browser_context.cc).
	// Enabling CT enforcement requires maintaining a log policy, and the ability to
	// update the list of accepted logs. Embedders who are planning to enable this
	// should first reach out to chrome-certificate-transparency@google.com.
	// On builds where CT is enabled, this flag is also used as an emergency kill
	// switch.
	BASE_FEATURE(kCertificateTransparencyAskBeforeEnabling,
	#if BUILDFLAG(GOOGLE_CHROME_BRANDING)
	base::FEATURE_ENABLED_BY_DEFAULT);
	#else
	base::FEATURE_DISABLED_BY_DEFAULT);
	#endif // BUILDFLAG(GOOGLE_CHROME_BRANDING)

	// Enables using network time for certificate verification. If enabled, network
	// time will be used to verify certificate validity, however certificates that
	// fail to validate with network time will fall back to the system time.
	// This has no effect if the network_time::kNetworkTimeServiceQuerying flag is
	// disabled, or the BrowserNetworkTimeQueriesEnabled policy is set to false.
	#if !BUILDFLAG(IS_CHROMEOS)
	BASE_FEATURE(kCertVerificationNetworkTime, base::FEATURE_ENABLED_BY_DEFAULT);
	#else
	BASE_FEATURE(kCertVerificationNetworkTime, base::FEATURE_DISABLED_BY_DEFAULT);
	#endif // !BUILDFLAG(IS_CHROMEOS)

	// Killswitch that guards clearing all user data in the ProfileImpl destructor.
	BASE_FEATURE(kClearUserDataUponProfileDestruction,
	base::FEATURE_ENABLED_BY_DEFAULT);

	#if BUILDFLAG(IS_LINUX)
	// Enables usage of os_crypt_async::SecretPortalKeyProvider. Once
	// `kSecretPortalKeyProviderUseForEncryption` is enabled, this flag cannot be
	// disabled without losing data.
	BASE_FEATURE(kDbusSecretPortal, base::FEATURE_ENABLED_BY_DEFAULT);

	// Enables usage of os_crypt_async::FreedesktopSecretKeyProvider, which is
	// compatible with the synchronous backend.
	BASE_FEATURE(kUseFreedesktopSecretKeyProvider,
	base::FEATURE_ENABLED_BY_DEFAULT);
	#endif // BUILDFLAG(IS_LINUX)

	// Destroy profiles when their last browser window is closed, instead of when
	// the browser exits.
	BASE_FEATURE(kDestroyProfileOnBrowserClose,
	#if BUILDFLAG(IS_LINUX) \|\| BUILDFLAG(IS_MAC) \|\| BUILDFLAG(IS_WIN)
	base::FEATURE_ENABLED_BY_DEFAULT);
	#else
	base::FEATURE_DISABLED_BY_DEFAULT);
	#endif

	// DestroyProfileOnBrowserClose only covers deleting regular (non-System)
	// Profiles. This flags lets us destroy the System Profile, as well.
	BASE_FEATURE(kDestroySystemProfiles, base::FEATURE_DISABLED_BY_DEFAULT);

	// Enables delaying the call to FullBrowserTransitionManager::OnProfileCreated()
	// until after BrowserContextDependencyManager::CreateBrowserContextServices()
	// in ProfileImpl::OnLocaleReady(). This change is thought to avoid creating
	// certain KeyedServices before they are properly initialized, but is flagged
	// guarded in case it causes unexpected issues.
	BASE_FEATURE(kDelayOnProfileCreatedForFullBrowserTransition,
	base::FEATURE_ENABLED_BY_DEFAULT);

	// Enables showing the email of the flex org admin that setup CBCM in the
	// management disclosures.
	BASE_FEATURE(kFlexOrgManagementDisclosure,
	#if BUILDFLAG(IS_CHROMEOS)
	base::FEATURE_DISABLED_BY_DEFAULT);
	#else
	base::FEATURE_ENABLED_BY_DEFAULT);
	#endif // BUILDFLAG(IS_CHROMEOS)

	// Enables the Incoming Call Notifications scenario. When created by an
	// installed origin, an incoming call notification should have increased
	// priority, colored buttons, a ringtone, and a default "close" button.
	// Otherwise, if the origin is not installed, it should behave like the default
	// notifications, but with the added "Close" button. See
	// https://github.com/MicrosoftEdge/MSEdgeExplainers/blob/main/Notifications/notifications_actions_customization.md
	BASE_FEATURE(kIncomingCallNotifications,
	#if BUILDFLAG(IS_WIN)
	base::FEATURE_ENABLED_BY_DEFAULT);
	#else
	base::FEATURE_DISABLED_BY_DEFAULT);
	#endif // BUILDFLAG(IS_WIN)

	#if BUILDFLAG(ENABLE_EXTENSIONS)
	BASE_FEATURE(kInitialExternalExtensions, base::FEATURE_ENABLED_BY_DEFAULT);
	#endif // BUILDFLAG(ENABLE_EXTENSIONS)

	#if !BUILDFLAG(IS_ANDROID)
	// Adds a "Snooze" action to mute notifications during screen sharing sessions.
	BASE_FEATURE(kMuteNotificationSnoozeAction, base::FEATURE_DISABLED_BY_DEFAULT);
	#endif

	// This feature enables monitoring of first-party network requests in order to
	// find possible violations. Example: A Chrome policy is set to disabled but the
	// network request controlled by that policy is observed.
	BASE_FEATURE(kNetworkAnnotationMonitoring, base::FEATURE_ENABLED_BY_DEFAULT);

	// This flag is used for enabling New Tab Page triggered prerendering. See
	// crbug.com/1462832 for more details of New Tab Page triggered prerendering.
	BASE_FEATURE(kNewTabPageTriggerForPrerender2, base::FEATURE_ENABLED_BY_DEFAULT);

	// This flag is used for enabling New Tab Page triggered prefetch. See
	// crbug.com/421941586 for more details of New Tab Page triggered prefetching.
	BASE_FEATURE(kNewTabPageTriggerForPrefetch, base::FEATURE_DISABLED_BY_DEFAULT);

	#if BUILDFLAG(IS_ANDROID)
	// Adds an "Unsubscribe" action to web push notifications that allows stopping
	// notifications from a given origin with a single tap (with an option to undo).
	BASE_FEATURE(kNotificationOneTapUnsubscribe, base::FEATURE_ENABLED_BY_DEFAULT);
	base::FeatureParam<bool> kNotificationOneTapUnsubscribeUseServiceIntentParam{
	&kNotificationOneTapUnsubscribe, "use_service_intent", false};
	#endif

	// Enables executing the browser commands sent by the NTP promos.
	BASE_FEATURE(kPromoBrowserCommands, base::FEATURE_ENABLED_BY_DEFAULT);

	// Parameter name for the promo browser command ID provided along with
	// kPromoBrowserCommands.
	// The value of this parameter should be parsable as an unsigned integer and
	// should map to one of the browser commands specified in:
	// ui/webui/resources/js/browser_command/browser_command.mojom
	const char kBrowserCommandIdParam[] = "BrowserCommandIdParam";

	#if BUILDFLAG(IS_WIN) && BUILDFLAG(GOOGLE_CHROME_BRANDING)
	// When this feature is enabled, Chrome will register os_update_handler with
	// Omaha, to be run on OS upgrade.
	BASE_FEATURE(kRegisterOsUpdateHandlerWin, base::FEATURE_ENABLED_BY_DEFAULT);
	// When this feature is enabled, Chrome will install the
	// platform_experience_helper.
	BASE_FEATURE(kInstallPlatformExperienceHelperWin,
	base::FEATURE_DISABLED_BY_DEFAULT);
	#endif // BUILDFLAG(IS_WIN) && BUILDFLAG(GOOGLE_CHROME_BRANDING)

	// When this feature is enabled, the network service will restart unsandboxed if
	// a previous attempt to launch it sandboxed failed.
	BASE_FEATURE(kRestartNetworkServiceUnsandboxedForFailedLaunch,
	base::FEATURE_ENABLED_BY_DEFAULT);

	// Gates sandboxed iframe navigation toward external protocol behind any of:
	// - allow-top-navigation
	// - allow-top-navigation-to-custom-protocols
	// - allow-top-navigation-with-user-gesture (+ user gesture)
	// - allow-popups
	//
	// Motivation:
	// Developers are surprised that a sandboxed iframe can navigate and/or
	// redirect the user toward an external application.
	// General iframe navigation in sandboxed iframe are not blocked normally,
	// because they stay within the iframe. However they can be seen as a popup or
	// a top-level navigation when it leads to opening an external application. In
	// this case, it makes sense to extend the scope of sandbox flags, to block
	// malvertising.
	//
	// Implementation bug: https://crbug.com/1253379
	// I2S: https://groups.google.com/a/chromium.org/g/blink-dev/c/-t-f7I6VvOI
	//
	// Enabled in M103. Flag to be removed in M106
	BASE_FEATURE(kSandboxExternalProtocolBlocked, base::FEATURE_ENABLED_BY_DEFAULT);
	// Enabled in M100. Flag to be removed in M106
	BASE_FEATURE(kSandboxExternalProtocolBlockedWarning,
	base::FEATURE_ENABLED_BY_DEFAULT);

	#if BUILDFLAG(IS_LINUX)
	// If true, encrypt new data with the key provided by SecretPortalKeyProvider.
	// Otherwise, it will only decrypt existing data.
	BASE_FEATURE(kSecretPortalKeyProviderUseForEncryption,
	base::FEATURE_DISABLED_BY_DEFAULT);

	// If true, encrypt new data with the key provided by
	// FreedesktopSecretKeyProvider. Otherwise, it will only decrypt existing data.
	BASE_FEATURE(kUseFreedesktopSecretKeyProviderForEncryption,
	base::FEATURE_ENABLED_BY_DEFAULT);
	#endif // BUILDFLAG(IS_LINUX)

	// Enables migration of the network context data from `unsandboxed_data_path` to
	// `data_path`. See the explanation in network_context.mojom.
	BASE_FEATURE(kTriggerNetworkDataMigration,
	#if BUILDFLAG(IS_WIN)
	base::FEATURE_ENABLED_BY_DEFAULT
	#else
	base::FEATURE_DISABLED_BY_DEFAULT
	#endif
	);

	#if BUILDFLAG(IS_CHROMEOS)
	// If enabled, a blue border is drawn around shared tabs on ChromeOS.
	// If disabled, the blue border is not used on ChromeOS.
	//
	// Motivation:
	// The blue border behavior used to (still does, see below) cause problems on
	// ChromeOS - see crbug.com/1320262 (fixed). This flag is introduced as means
	// of disabling this feature in case of possible future regressions.
	//
	// TODO(crbug.com/40198577): Remove this flag once we confirm that blue border
	// works fine on ChromeOS.
	//
	// b/279051234: We suspect the tab sharing blue border may cause a bad issue
	// on ChromeOS where a window can not be interacted at all. Disable the feature
	// on ChromeOS.
	BASE_FEATURE(kTabCaptureBlueBorderCrOS, base::FEATURE_DISABLED_BY_DEFAULT);
	#endif

	// Enables runtime detection of USB devices which provide a WebUSB landing page
	// descriptor.
	BASE_FEATURE(kWebUsbDeviceDetection, base::FEATURE_ENABLED_BY_DEFAULT);

	#if BUILDFLAG(IS_WIN)
	// Disable dynamic code using ACG. Prevents the browser process from generating
	// dynamic code or modifying executable code. See comments in
	// sandbox/win/src/security_level.h. Only available on Windows 10 RS1 (1607,
	// Build 14393) onwards.
	BASE_FEATURE(kBrowserDynamicCodeDisabled, base::FEATURE_DISABLED_BY_DEFAULT);

	// The Chrome DLL can be pre-read with ::PrefetchVirtualMemory() from the
	// browser or a child process. Pre-reading is supposed to bring the whole DLL in
	// physical memory more efficiently than a series of hard faults. However,
	// pre-reading consumes a non-trivial amount of CPU even when the DLL is already
	// in physical memory and it may not be necessary to have the full DLL in
	// physical memory (space taken by unused parts of the DLL could potentially be
	// used for more important stuff). This file has multiple features to experiment
	// with policies for pre-reading the Chrome DLL in child processes. The
	// `kPrefetchVirtualMemoryPolicy` feature defined elsewhere controls pre-reading
	// the Chrome DLL from the browser process.

	// When enabled, child processes never pre-read the Chrome DLL.
	BASE_FEATURE(kNoPreReadMainDll, base::FEATURE_DISABLED_BY_DEFAULT);

	// When enabled, child processes don't pre-read the Chrome DLL if we believe the
	// Chrome DLL is on an SSD (i.e. pre-read only on spinning disk).
	BASE_FEATURE(kNoPreReadMainDllIfSsd, base::FEATURE_ENABLED_BY_DEFAULT);

	// When enabled, the browser process suppresses pre-read in child processes
	// shortly after browser startup, where "shortly after" is dictated by the
	// feature param below. This is thought to be a productive strategy since the
	// browser process will have recently pre-read the DLL during browser
	// startup. In that case, the browser process has recently pre-read the DLL so
	// pre-reading again is thought to be counter-productive (CPU consumption for no
	// gains).
	BASE_FEATURE(kNoPreReadMainDllStartup, base::FEATURE_DISABLED_BY_DEFAULT);

	// Time after browser startup during which child processes don't pre-read the
	// Chrome DLL when `kNoPreReadMainDllStartup` is enabled.
	const base::FeatureParam<base::TimeDelta>
	kNoPreReadMainDllStartup_StartupDuration{&kNoPreReadMainDllStartup,
	"no-preread-dll-startup-time",
	base::Minutes(2)};

	// When enabled, the browser process will re-launch itself when launched with
	// an elevated linked token. The re-launched browser will use the token from
	// the Windows Shell (explorer.exe), which is typically non-elevated.
	BASE_FEATURE(kAutoDeElevate, base::FEATURE_ENABLED_BY_DEFAULT);
	#endif // BUILDFLAG(IS_WIN)

	#if !BUILDFLAG(IS_ANDROID)
	// This flag controls whether to perform Pak integrity check on startup to
	// report statistics for on-disk corruption.
	// Disabled on ChromeOS, as dm-verity enforces integrity and the check would
	// be redundant.
	BASE_FEATURE(kReportPakFileIntegrity,
	#if !BUILDFLAG(IS_CHROMEOS)
	base::FEATURE_ENABLED_BY_DEFAULT);
	#else
	base::FEATURE_DISABLED_BY_DEFAULT);
	#endif // BUILDFLAG(IS_CHROMEOS)
	#endif // BUILDFLAG(IS_ANDROID)

	// This flag enables the removal of IWAs surface captures from Chrome Tabs
	// category in getDisplayMedia() API. When disabled, IWAs surface captures
	// show both in Chrome Tabs and Windows.
	BASE_FEATURE(kRemovalOfIWAsFromTabCapture, base::FEATURE_ENABLED_BY_DEFAULT);

	} // namespace features