Remove WebComponentsV0 feature (mostly impacts WebView)

This CL removes the WebComponentsV0 feature added in [1] for
WebView. This was a temporary feature, to enable developers to
control these features starting in M86, because a Finch config
began disabling M86 Web Components for all users. Now that M86
(and M87) are out of Dev, this CL removes this feature flag
completely.

[1] https://chromium-review.googlesource.com/c/chromium/src/+/2268544

Bug: 1021631, 1021631
Change-Id: Ie6d14040105f2a239b8f95caae88a95d1da1f7b0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2514590Reviewed-by: Scott Violet <sky@chromium.org>
Reviewed-by: Nate Fischer <ntfschr@chromium.org>
Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Auto-Submit: Mason Freed <masonfreed@chromium.org>
Commit-Queue: Mason Freed <masonfreed@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824056}

android_webview/browser/aw_settings.cc

@@ -45,7 +45,6 @@ void PopulateFixedWebPreferences(WebPreferences* web_prefs) {
   web_prefs->disable_features_depending_on_viz =
       !::features::IsUsingVizForWebView();
   web_prefs->disable_accelerated_small_canvases = true;
-  web_prefs->reenable_web_components_v0 = true;
   // WebView has historically not adjusted font scale for text autosizing.
   web_prefs->device_scale_adjustment = 1.0;
 }

android_webview/java/src/org/chromium/android_webview/common/ProductionSupportedFlagList.java

@@ -91,9 +91,6 @@ public final class ProductionSupportedFlagList {
                             + "of the total screen size. Depending on the number of WebViews and "
                             + "the size of the screen this might be expensive so hidden behind a "
                             + "feature flag until the true runtime cost can be measured."),
-            Flag.baseFeature(BlinkFeatures.WEB_COMPONENTS_V0,
-                    "Re-enables the deprecated Web Components v0 features (Shadow DOM v0, Custom "
-                            + "Elements v0, and HTML Imports)."),
             Flag.baseFeature(AwFeatures.WEBVIEW_DISPLAY_CUTOUT,
                     "Enables display cutout (notch) support in WebView for Android P and above."),
             Flag.baseFeature(AwFeatures.WEBVIEW_CPU_AFFINITY_RESTRICT_TO_LITTLE_CORES,

content/child/runtime_features.cc

@@ -299,9 +299,6 @@ void SetRuntimeFeaturesFromChromiumFeatures() {
     {wf::EnableDocumentPolicyNegotiation, features::kDocumentPolicyNegotiation},
     {wf::EnableScrollUnification, features::kScrollUnification},
     {wf::EnableNeverSlowMode, features::kNeverSlowMode},
-    {wf::EnableShadowDOMV0, blink::features::kWebComponentsV0},
-    {wf::EnableCustomElementsV0, blink::features::kWebComponentsV0},
-    {wf::EnableHTMLImports, blink::features::kWebComponentsV0},
     {wf::EnableVideoPlaybackQuality, features::kVideoPlaybackQuality},
     {wf::EnableBrowserVerifiedUserActivationKeyboard,
      features::kBrowserVerifiedUserActivationKeyboard},
@@ -351,7 +348,6 @@ void SetRuntimeFeaturesFromChromiumFeatures() {
            blink::features::kCSSReducedFontLoadingLayoutInvalidations},
           {"CSSMatchedPropertiesCacheDependencies",
            blink::features::kCSSMatchedPropertiesCacheDependencies},
-          {"CustomElementsV0", blink::features::kWebComponentsV0},
           {"FeaturePolicyForClientHints",
            features::kFeaturePolicyForClientHints},
           {"EditingNG", blink::features::kEditingNG},
@@ -360,7 +356,6 @@ void SetRuntimeFeaturesFromChromiumFeatures() {
           {"FontSrcLocalMatching", features::kFontSrcLocalMatching},
           {"ForceSynchronousHTMLParsing",
            blink::features::kForceSynchronousHTMLParsing},
-          {"HTMLImports", blink::features::kWebComponentsV0},
           {"IgnoreCrossOriginWindowWhenNamedAccessOnWindow",
            blink::features::kIgnoreCrossOriginWindowWhenNamedAccessOnWindow},
           {"LangClientHintHeader", features::kLangClientHintHeader},
@@ -376,7 +371,6 @@ void SetRuntimeFeaturesFromChromiumFeatures() {
           {"ParentNodeReplaceChildren",
            blink::features::kParentNodeReplaceChildren},
           {"RawClipboard", blink::features::kRawClipboard},
-          {"ShadowDOMV0", blink::features::kWebComponentsV0},
           {"StorageAccessAPI", blink::features::kStorageAccessAPI},
           {"TrustedDOMTypes", features::kTrustedDOMTypes},
           {"UserAgentClientHint", features::kUserAgentClientHint},

third_party/blink/common/features.cc

@@ -306,10 +306,6 @@ const base::Feature kFontAccess{"FontAccess",
 const base::Feature kFontAccessChooser{"FontAccessChooser",
                                        base::FEATURE_DISABLED_BY_DEFAULT};
 
-// Allows Web Components v0 to be re-enabled.
-const base::Feature kWebComponentsV0{"WebComponentsV0",
-                                     base::FEATURE_DISABLED_BY_DEFAULT};
-
 // Prefetch request properties are updated to be privacy-preserving. See
 // crbug.com/988956.
 const base::Feature kPrefetchPrivacyChanges{"PrefetchPrivacyChanges",

third_party/blink/common/web_preferences/web_preferences.cc

@@ -185,7 +185,6 @@ WebPreferences::WebPreferences()
       scroll_top_left_interop_enabled(true),
       disable_features_depending_on_viz(false),
       disable_accelerated_small_canvases(false),
-      reenable_web_components_v0(false),
 #endif  // defined(OS_ANDROID)
 #if defined(OS_ANDROID)
       default_minimum_page_scale_factor(0.25f),

third_party/blink/common/web_preferences/web_preferences_mojom_traits.cc

@@ -316,7 +316,6 @@ bool StructTraits<blink::mojom::WebPreferencesDataView,
       data.disable_features_depending_on_viz();
   out->disable_accelerated_small_canvases =
       data.disable_accelerated_small_canvases();
-  out->reenable_web_components_v0 = data.reenable_web_components_v0();
 #endif
   out->force_dark_mode_enabled = data.force_dark_mode_enabled();
   out->default_minimum_page_scale_factor =

third_party/blink/public/common/features.h

@@ -87,8 +87,6 @@ BLINK_COMMON_EXPORT extern const base::Feature kFileHandlingAPI;
 BLINK_COMMON_EXPORT extern const base::Feature kAllowSyncXHRInPageDismissal;
 BLINK_COMMON_EXPORT extern const base::Feature kPrefetchPrivacyChanges;
 
-BLINK_COMMON_EXPORT extern const base::Feature kWebComponentsV0;
-
 BLINK_COMMON_EXPORT extern const char kMixedContentAutoupgradeModeParamName[];
 BLINK_COMMON_EXPORT extern const char kMixedContentAutoupgradeModeAllPassive[];
 

third_party/blink/public/common/web_preferences/web_preferences.h

@@ -255,9 +255,6 @@ struct BLINK_COMMON_EXPORT WebPreferences {
   bool disable_features_depending_on_viz;
   // Don't accelerate small canvases to avoid crashes TODO(crbug.com/1004304)
   bool disable_accelerated_small_canvases;
-  // Re-enable Web Components v0 on Webview, temporarily. This should get
-  // removed when crbug.com/1021631 gets fixed.
-  bool reenable_web_components_v0;
 #endif  // defined(OS_ANDROID)
 
   // Enable forcibly modifying content rendering to result in a light on dark

third_party/blink/public/common/web_preferences/web_preferences_mojom_traits.h

@@ -673,11 +673,6 @@ struct BLINK_COMMON_EXPORT StructTraits<blink::mojom::WebPreferencesDataView,
       const blink::web_pref::WebPreferences& r) {
     return r.disable_accelerated_small_canvases;
   }
-
-  static bool reenable_web_components_v0(
-      const blink::web_pref::WebPreferences& r) {
-    return r.reenable_web_components_v0;
-  }
 #endif
 
   static bool force_dark_mode_enabled(

third_party/blink/public/mojom/webpreferences/web_preferences.mojom

@@ -349,11 +349,6 @@ struct WebPreferences {
   // Don't accelerate small canvases to avoid crashes TODO(crbug.com/1004304)
   bool disable_accelerated_small_canvases;
 
-  // Re-enable Web Components v0 on Webview, temporarily. This should get
-  // removed when crbug.com/1021631 gets fixed.
-  [EnableIf=is_android]
-  bool reenable_web_components_v0;
-
   // Enable forcibly modifying content rendering to result in a light on dark
   // color scheme.
   bool force_dark_mode_enabled;

third_party/blink/renderer/core/exported/web_view_impl.cc

@@ -2120,11 +2120,6 @@ void WebView::ApplyWebPreferences(const web_pref::WebPreferences& prefs,
       !prefs.disable_features_depending_on_viz);
   WebRuntimeFeatures::EnableAcceleratedSmallCanvases(
       !prefs.disable_accelerated_small_canvases);
-  if (prefs.reenable_web_components_v0) {
-    WebRuntimeFeatures::EnableShadowDOMV0(true);
-    WebRuntimeFeatures::EnableCustomElementsV0(true);
-    WebRuntimeFeatures::EnableHTMLImports(true);
-  }
 #endif  // defined(OS_ANDROID)
   settings->SetForceDarkModeEnabled(prefs.force_dark_mode_enabled);