[CodeHealth] Remove experimental flag UserActivationPostMessageTransfer

We have already removed all the transferring user activation code, and
this CL removes experimental flag UserActivationPostMessageTransfer.

Bug: 1067307
Change-Id: Ib444f2ce158a19c1d60f971e461c4a4e59c41a80
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2291353Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Mustaq Ahmed <mustaq@chromium.org>
Commit-Queue: Lan Wei <lanwei@chromium.org>
Cr-Commit-Position: refs/heads/master@{#793022}

content/child/runtime_features.cc

@@ -221,8 +221,6 @@ void SetRuntimeFeaturesFromChromiumFeatures() {
     {wf::EnableWebXRPlaneDetection, features::kWebXrIncubations, kEnableOnly},
     {wf::EnableWebXRReflectionEstimation, features::kWebXrIncubations,
      kEnableOnly},
-    {wf::EnableUserActivationPostMessageTransfer,
-     features::kUserActivationPostMessageTransfer, kUseFeatureState},
     {wf::EnableUserActivationSameOriginVisibility,
      features::kUserActivationSameOriginVisibility, kUseFeatureState},
     {wf::EnableExpensiveBackgroundTimerThrottling,

content/public/common/content_features.cc

@@ -702,11 +702,6 @@ const base::Feature kTrustedDOMTypes{"TrustedDOMTypes",
 const base::Feature kUseFramePriorityInRenderProcessHost{
     "UseFramePriorityInRenderProcessHost", base::FEATURE_DISABLED_BY_DEFAULT};
 
-// Allows developers transfer user activation state to any target window in the
-// frame tree.
-const base::Feature kUserActivationPostMessageTransfer{
-    "UserActivationPostMessageTransfer", base::FEATURE_DISABLED_BY_DEFAULT};
-
 // Allows user activation propagation to all frames having the same origin as
 // the activation notifier frame.  This is an intermediate measure before we
 // have an iframe attribute to declaratively allow user activation propagation

content/public/common/content_features.h

@@ -149,7 +149,6 @@ CONTENT_EXPORT extern const base::Feature kTouchpadAsyncPinchEvents;
 CONTENT_EXPORT extern const base::Feature kTouchpadOverscrollHistoryNavigation;
 CONTENT_EXPORT extern const base::Feature kTrustedDOMTypes;
 CONTENT_EXPORT extern const base::Feature kUseFramePriorityInRenderProcessHost;
-CONTENT_EXPORT extern const base::Feature kUserActivationPostMessageTransfer;
 CONTENT_EXPORT extern const base::Feature kUserActivationSameOriginVisibility;
 CONTENT_EXPORT extern const base::Feature kUserAgentClientHint;
 CONTENT_EXPORT extern const base::Feature kVideoPlaybackQuality;

third_party/blink/public/platform/web_runtime_features.h

@@ -167,8 +167,6 @@ class WebRuntimeFeatures {
   BLINK_PLATFORM_EXPORT static void EnableTextFragmentAnchor(bool);
   BLINK_PLATFORM_EXPORT static void EnableTouchEventFeatureDetection(bool);
   BLINK_PLATFORM_EXPORT static void EnableScrollUnification(bool);
-  BLINK_PLATFORM_EXPORT static void EnableUserActivationPostMessageTransfer(
-      bool);
   BLINK_PLATFORM_EXPORT static void EnableUserActivationSameOriginVisibility(
       bool);
   BLINK_PLATFORM_EXPORT static void EnableV8IdleTasks(bool);

third_party/blink/renderer/core/frame/window_post_message_options.idl

@@ -6,5 +6,4 @@
 
 dictionary WindowPostMessageOptions : PostMessageOptions {
     USVString targetOrigin = "/";
-    [RuntimeEnabled=UserActivationPostMessageTransfer] boolean transferUserActivation = false;
 };

third_party/blink/renderer/platform/exported/web_runtime_features.cc

@@ -379,10 +379,6 @@ void WebRuntimeFeatures::EnableScriptedSpeechSynthesis(bool enable) {
   RuntimeEnabledFeatures::SetScriptedSpeechSynthesisEnabled(enable);
 }
 
-void WebRuntimeFeatures::EnableUserActivationPostMessageTransfer(bool enable) {
-  RuntimeEnabledFeatures::SetUserActivationPostMessageTransferEnabled(enable);
-}
-
 void WebRuntimeFeatures::EnableUserActivationSameOriginVisibility(bool enable) {
   RuntimeEnabledFeatures::SetUserActivationSameOriginVisibilityEnabled(enable);
 }

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -1884,9 +1884,6 @@
       origin_trial_feature_name: "UnsizedMediaPolicy",
       implied_by: ["ExperimentalProductivityFeatures"]
     },
-    {
-      name: "UserActivationPostMessageTransfer",
-    },
     {
       name: "UserActivationSameOriginVisibility",
     },