android_webview/browser/aw_field_trials.cc

// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "android_webview/browser/aw_field_trials.h"

#include "android_webview/common/aw_features.h"
#include "android_webview/common/aw_switches.h"
#include "base/allocator/partition_alloc_features.h"
#include "base/base_paths_android.h"
#include "base/check.h"
#include "base/metrics/field_trial_params.h"
#include "base/metrics/persistent_histogram_allocator.h"
#include "base/path_service.h"
#include "components/history/core/browser/features.h"
#include "components/metrics/persistent_histograms.h"
#include "components/permissions/features.h"
#include "components/safe_browsing/core/common/features.h"
#include "components/translate/core/common/translate_util.h"
#include "components/viz/common/features.h"
#include "content/public/common/content_features.h"
#include "gpu/config/gpu_finch_features.h"
#include "media/base/media_switches.h"
#include "mojo/public/cpp/bindings/features.h"
#include "net/base/features.h"
#include "services/network/public/cpp/features.h"
#include "third_party/blink/public/common/features.h"
#include "third_party/blink/public/common/features_generated.h"
#include "ui/android/ui_android_features.h"
#include "ui/gl/gl_features.h"

namespace internal {

AwFeatureOverrides::AwFeatureOverrides(base::FeatureList& feature_list)
    : feature_list_(feature_list) {}

AwFeatureOverrides::~AwFeatureOverrides() {
  // TODO(crbug.com/379864779): This doesn't play well with potential server-
  // side overrides.
  for (const auto& field_trial_override : field_trial_overrides_) {
    feature_list_->RegisterFieldTrialOverride(
        field_trial_override.feature->name, field_trial_override.override_state,
        field_trial_override.field_trial);
  }
  feature_list_->RegisterExtraFeatureOverrides(
      std::move(overrides_), /*replace_use_default_overrides=*/true);
}

void AwFeatureOverrides::EnableFeature(const base::Feature& feature) {
  overrides_.emplace_back(
      std::cref(feature),
      base::FeatureList::OverrideState::OVERRIDE_ENABLE_FEATURE);
}

void AwFeatureOverrides::DisableFeature(const base::Feature& feature) {
  overrides_.emplace_back(
      std::cref(feature),
      base::FeatureList::OverrideState::OVERRIDE_DISABLE_FEATURE);
}

void AwFeatureOverrides::OverrideFeatureWithFieldTrial(
    const base::Feature& feature,
    base::FeatureList::OverrideState override_state,
    base::FieldTrial* field_trial) {
  field_trial_overrides_.emplace_back(FieldTrialOverride{
      .feature = raw_ref(feature),
      .override_state = override_state,
      .field_trial = field_trial,
  });
}

}  // namespace internal

void AwFieldTrials::OnVariationsSetupComplete() {
  // Persistent histograms must be enabled ASAP, but depends on Features.
  base::FilePath metrics_dir;
  if (base::PathService::Get(base::DIR_ANDROID_APP_DATA, &metrics_dir)) {
    InstantiatePersistentHistogramsWithFeaturesAndCleanup(metrics_dir);
  } else {
    NOTREACHED();
  }
}

// TODO(crbug.com/40271903): Consider to migrate all WebView feature overrides
// from the AwMainDelegate to the new mechanism here.
void AwFieldTrials::RegisterFeatureOverrides(base::FeatureList* feature_list) {
  if (!feature_list) {
    return;
  }
  internal::AwFeatureOverrides aw_feature_overrides(*feature_list);

  // Disable third-party storage partitioning on WebView.
  aw_feature_overrides.DisableFeature(
      net::features::kThirdPartyStoragePartitioning);

  // Disable the passthrough on WebView.
  aw_feature_overrides.DisableFeature(
      ::features::kDefaultPassthroughCommandDecoder);

  // HDR does not support webview yet. See crbug.com/1493153 for an explanation.
  aw_feature_overrides.DisableFeature(ui::kAndroidHDR);

  // Disable Reducing User Agent minor version on WebView.
  aw_feature_overrides.DisableFeature(
      blink::features::kReduceUserAgentMinorVersion);

  // Disable fenced frames on WebView.
  aw_feature_overrides.DisableFeature(blink::features::kFencedFrames);

  // Disable FLEDGE on WebView.
  aw_feature_overrides.DisableFeature(blink::features::kAdInterestGroupAPI);
  aw_feature_overrides.DisableFeature(blink::features::kFledge);

  // Disable low latency overlay for WebView. There is currently no plan to
  // enable these optimizations in WebView though they are not fundamentally
  // impossible.
  aw_feature_overrides.DisableFeature(
      blink::features::kLowLatencyCanvas2dImageChromium);
  aw_feature_overrides.DisableFeature(
      blink::features::kLowLatencyWebGLImageChromium);

  // Disable Shared Storage on WebView.
  aw_feature_overrides.DisableFeature(blink::features::kSharedStorageAPI);

  // Disable scrollbar-color on WebView.
  aw_feature_overrides.DisableFeature(blink::features::kScrollbarColor);

  // Disable scrollbar-width on WebView.
  aw_feature_overrides.DisableFeature(blink::features::kScrollbarWidth);

  // Disable Populating the VisitedLinkDatabase on WebView.
  aw_feature_overrides.DisableFeature(history::kPopulateVisitedLinkDatabase);

  // WebView uses kWebViewVulkan to control vulkan. Pre-emptively disable
  // kVulkan in case it becomes enabled by default.
  aw_feature_overrides.DisableFeature(::features::kVulkan);

  aw_feature_overrides.DisableFeature(::features::kWebPayments);
  aw_feature_overrides.DisableFeature(::features::kServiceWorkerPaymentApps);

  // WebView does not support overlay fullscreen yet for video overlays.
  aw_feature_overrides.DisableFeature(media::kOverlayFullscreenVideo);

  // WebView does not support EME persistent license yet, because it's not
  // clear on how user can remove persistent media licenses from UI.
  aw_feature_overrides.DisableFeature(media::kMediaDrmPersistentLicense);

  // WebView does not support multiple processes, so don't try to call some
  // MediaDrm APIs in a separate process.
  aw_feature_overrides.DisableFeature(
      media::kAllowMediaCodecCallsInSeparateProcess);

  aw_feature_overrides.DisableFeature(::features::kBackgroundFetch);

  // SurfaceControl is controlled by kWebViewSurfaceControl flag.
  aw_feature_overrides.DisableFeature(::features::kAndroidSurfaceControl);

  // TODO(crbug.com/40627649): WebOTP is not yet supported on
  // WebView.
  aw_feature_overrides.DisableFeature(::features::kWebOTP);

  // TODO(crbug.com/40652382): WebXR is not yet supported on WebView.
  aw_feature_overrides.DisableFeature(::features::kWebXr);

  // TODO(crbug.com/40831925): Digital Goods API is not yet supported
  // on WebView.
  aw_feature_overrides.DisableFeature(::features::kDigitalGoodsApi);

  aw_feature_overrides.DisableFeature(::features::kDynamicColorGamut);

  // COOP is not supported on WebView yet. See:
  // https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/XBKAGb2_7uAi.
  aw_feature_overrides.DisableFeature(
      network::features::kCrossOriginOpenerPolicy);

  aw_feature_overrides.DisableFeature(::features::kInstalledApp);

  aw_feature_overrides.DisableFeature(::features::kPeriodicBackgroundSync);

  // Disabled until viz scheduling can be improved.
  aw_feature_overrides.DisableFeature(
      ::features::kUseSurfaceLayerForVideoDefault);

  // Disable dr-dc on webview.
  aw_feature_overrides.DisableFeature(::features::kEnableDrDc);

  // TODO(crbug.com/40703318): Web Bluetooth is not yet supported on WebView.
  aw_feature_overrides.DisableFeature(::features::kWebBluetooth);

  // TODO(crbug.com/41441927): WebUSB is not yet supported on WebView.
  aw_feature_overrides.DisableFeature(::features::kWebUsb);

  // Disable TFLite based language detection on webview until webview supports
  // ML model delivery via Optimization Guide component.
  // TODO(crbug.com/40819484): Enable the feature on Webview.
  aw_feature_overrides.DisableFeature(
      ::translate::kTFLiteLanguageDetectionEnabled);

  // Disable key pinning enforcement on webview.
  aw_feature_overrides.DisableFeature(
      net::features::kStaticKeyPinningEnforcement);

  // FedCM is not yet supported on WebView.
  aw_feature_overrides.DisableFeature(::features::kFedCm);
  aw_feature_overrides.DisableFeature(
      blink::features::kFedCmWithStorageAccessAPI);

  // TODO(crbug.com/40272633): Web MIDI permission prompt for all usage.
  aw_feature_overrides.DisableFeature(blink::features::kBlockMidiByDefault);

  // Disable device posture API as the framework implementation causes
  // AwContents to leak in apps that don't call destroy().
  aw_feature_overrides.DisableFeature(blink::features::kDevicePosture);
  aw_feature_overrides.DisableFeature(blink::features::kViewportSegments);

  // PaintHolding for OOPIFs. This should be a no-op since WebView doesn't use
  // site isolation but field trial testing doesn't indicate that. Revisit when
  // enabling site isolation. See crbug.com/356170748.
  aw_feature_overrides.DisableFeature(blink::features::kPaintHoldingForIframes);

  // Since Default Nav Transition does not support WebView yet, disable the
  // LocalSurfaceId increment flag. TODO(crbug.com/361600214): Re-enable for
  // WebView when we start introducing this feature.
  aw_feature_overrides.DisableFeature(
      blink::features::kIncrementLocalSurfaceIdForMainframeSameDocNavigation);

  // Disabling this feature for WebView, since it can switch focus when scrolled
  // in cases with multiple views which can trigger HTML focus changes that
  // aren't intended. See crbug.com/378779896, crbug.com/373672168 for more
  // details.
  aw_feature_overrides.DisableFeature(
      ::features::kFocusRenderWidgetHostViewAndroidOnActionDown);

  if (base::CommandLine::ForCurrentProcess()->HasSwitch(switches::kDebugBsa)) {
    // Feature parameters can only be set via a field trial.
    const char kTrialName[] = "StudyDebugBsa";
    const char kGroupName[] = "GroupDebugBsa";
    base::FieldTrial* field_trial =
        base::FieldTrialList::CreateFieldTrial(kTrialName, kGroupName);
    // If field_trial is null, there was some unexpected name conflict.
    CHECK(field_trial);
    base::FieldTrialParams params;
    params.emplace(net::features::kIpPrivacyTokenServer.name,
                   "https://staging-phosphor-pa.sandbox.googleapis.com");
    base::AssociateFieldTrialParams(kTrialName, kGroupName, params);
    aw_feature_overrides.OverrideFeatureWithFieldTrial(
        net::features::kEnableIpProtectionProxy,
        base::FeatureList::OverrideState::OVERRIDE_ENABLE_FEATURE, field_trial);
    aw_feature_overrides.EnableFeature(network::features::kMaskedDomainList);
  }

  // Feature parameters can only be set via a field trial.
  // Note: Performing a field trial here means we cannot include
  // |kDIPSTtl| in the testing config json.
  {
    const char kDipsWebViewExperiment[] = "DipsWebViewExperiment";
    const char kDipsWebViewGroup[] = "DipsWebViewGroup";
    base::FieldTrial* dips_field_trial = base::FieldTrialList::CreateFieldTrial(
        kDipsWebViewExperiment, kDipsWebViewGroup);
    CHECK(dips_field_trial) << "Unexpected name conflict.";
    base::FieldTrialParams params;
    const std::string ttl_time_delta_30_days = "30d";
    params.emplace(features::kDIPSInteractionTtl.name, ttl_time_delta_30_days);
    base::AssociateFieldTrialParams(kDipsWebViewExperiment, kDipsWebViewGroup,
                                    params);
    aw_feature_overrides.OverrideFeatureWithFieldTrial(
        features::kDIPSTtl,
        base::FeatureList::OverrideState::OVERRIDE_ENABLE_FEATURE,
        dips_field_trial);
  }

  // Delete Incidental Party State (DIPS) feature is not yet supported on
  // WebView.
  aw_feature_overrides.DisableFeature(::features::kDIPS);

  // These features have shown performance improvements in WebView but not some
  // other platforms.
  aw_feature_overrides.EnableFeature(features::kEnsureExistingRendererAlive);
  aw_feature_overrides.EnableFeature(blink::features::kThreadedBodyLoader);
  aw_feature_overrides.EnableFeature(blink::features::kThreadedPreloadScanner);
  aw_feature_overrides.EnableFeature(blink::features::kPrecompileInlineScripts);

  // This feature has not been experimented with yet on WebView.
  // TODO(crbug.com/336852432): Enable this feature for WebView.
  aw_feature_overrides.DisableFeature(
      blink::features::kNavigationPredictorNewViewportFeatures);

  // This feature is global for the process and thus should not be enabled by
  // WebView.
  aw_feature_overrides.DisableFeature(
      base::features::kPartitionAllocMemoryTagging);

  // Disable Topics on WebView.
  aw_feature_overrides.DisableFeature(blink::features::kBrowsingTopics);
}