Add Skip Ad Origin Trial

This CL removes the SkipAd media switch feature as the
Picture-in-Picture window will receive events only from blink/.

Intent to Experiment: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/l6sW0G4jzhE

Bug: 910436
Change-Id: I4c41b476691f43d76a8811f8990873c222341e7c
Reviewed-on: https://chromium-review.googlesource.com/c/1452186
Commit-Queue: François Beaufort <beaufort.francois@gmail.com>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Jochen Eisinger <jochen@chromium.org>
Reviewed-by: Ian Clelland <iclelland@chromium.org>
Cr-Commit-Position: refs/heads/master@{#629946}

chrome/browser/picture_in_picture/picture_in_picture_window_controller_browsertest.cc

@@ -1894,9 +1894,9 @@ class MediaSessionPictureInPictureWindowControllerBrowserTest
   void SetUpCommandLine(base::CommandLine* command_line) override {
     PictureInPictureWindowControllerBrowserTest::SetUpCommandLine(command_line);
     command_line->AppendSwitchASCII(switches::kEnableBlinkFeatures,
-                                    "MediaSession");
+                                    "MediaSession,SkipAd");
     scoped_feature_list_.InitWithFeatures(
-        {media_session::features::kMediaSessionService, media::kSkipAd}, {});
+        {media_session::features::kMediaSessionService}, {});
   }
 
  private:

chrome/browser/ui/views/overlay/overlay_window_views.cc

@@ -647,8 +647,7 @@ void OverlayWindowViews::SetAlwaysHidePlayPauseButton(bool is_visible) {
 }
 
 void OverlayWindowViews::SetSkipAdButtonVisibility(bool is_visible) {
-  if (base::FeatureList::IsEnabled(media::kSkipAd))
-    show_skip_ad_button_ = is_visible;
+  show_skip_ad_button_ = is_visible;
 }
 
 void OverlayWindowViews::SetPictureInPictureCustomControls(

content/browser/picture_in_picture/picture_in_picture_window_controller_impl.cc

@@ -226,8 +226,7 @@ void PictureInPictureWindowControllerImpl::SetAlwaysHidePlayPauseButton(
 }
 
 void PictureInPictureWindowControllerImpl::SkipAd() {
-  if (base::FeatureList::IsEnabled(media::kSkipAd) &&
-      media_session_action_skip_ad_handled_)
+  if (media_session_action_skip_ad_handled_)
     MediaSession::Get(initiator_)->SkipAd();
 }
 

media/base/media_switches.cc

@@ -204,9 +204,6 @@ const base::Feature kPictureInPicture {
 #endif
 };
 
-// Show Skip Ad button in Picture-in-Picture window.
-const base::Feature kSkipAd{"SkipAd", base::FEATURE_DISABLED_BY_DEFAULT};
-
 // Only decode preload=metadata elements upon visibility?
 const base::Feature kPreloadMetadataLazyLoad{"PreloadMetadataLazyLoad",
                                              base::FEATURE_DISABLED_BY_DEFAULT};

media/base/media_switches.h

@@ -130,7 +130,6 @@ MEDIA_EXPORT extern const base::Feature kRecordMediaEngagementScores;
 MEDIA_EXPORT extern const base::Feature kRecordWebAudioEngagement;
 MEDIA_EXPORT extern const base::Feature kResumeBackgroundVideo;
 MEDIA_EXPORT extern const base::Feature kSpecCompliantCanPlayThrough;
-MEDIA_EXPORT extern const base::Feature kSkipAd;
 MEDIA_EXPORT extern const base::Feature kUnifiedAutoplay;
 MEDIA_EXPORT extern const base::Feature kUseAndroidOverlay;
 MEDIA_EXPORT extern const base::Feature kUseAndroidOverlayAggressively;

third_party/blink/public/platform/web_feature.mojom

@@ -2220,6 +2220,7 @@ enum WebFeature {
   kV8RemotePlayback_WatchAvailability_Method = 2780,
   kV8RemotePlayback_Prompt_Method = 2781,
   kLayoutJankExplicitlyRequested = 2782,
+  kMediaSessionSkipAd = 2783,
 
   // Add new features immediately above this line. Don't change assigned
   // numbers of any item, and don't reuse removed slots.

third_party/blink/renderer/modules/mediasession/media_session.cc

@@ -13,8 +13,11 @@
 #include "third_party/blink/renderer/core/dom/user_gesture_indicator.h"
 #include "third_party/blink/renderer/core/execution_context/execution_context.h"
 #include "third_party/blink/renderer/core/frame/local_frame.h"
+#include "third_party/blink/renderer/core/frame/use_counter.h"
+#include "third_party/blink/renderer/core/origin_trials/origin_trials.h"
 #include "third_party/blink/renderer/modules/mediasession/media_metadata.h"
 #include "third_party/blink/renderer/modules/mediasession/media_metadata_sanitizer.h"
+#include "third_party/blink/renderer/platform/bindings/exception_state.h"
 
 namespace blink {
 
@@ -156,7 +159,19 @@ void MediaSession::OnMetadataChanged() {
 }
 
 void MediaSession::setActionHandler(const String& action,
-                                    V8MediaSessionActionHandler* handler) {
+                                    V8MediaSessionActionHandler* handler,
+                                    ExceptionState& exception_state) {
+  if (action == "skipad") {
+    if (!origin_trials::SkipAdEnabled(GetExecutionContext())) {
+      exception_state.ThrowTypeError(
+          "The provided value 'skipad' is not a valid enum "
+          "value of type MediaSessionAction.");
+      return;
+    }
+
+    UseCounter::Count(GetExecutionContext(), WebFeature::kMediaSessionSkipAd);
+  }
+
   if (handler) {
     auto add_result = action_handlers_.Set(action, handler);
 

third_party/blink/renderer/modules/mediasession/media_session.h

@@ -18,6 +18,7 @@
 namespace blink {
 
 class ExecutionContext;
+class ExceptionState;
 class MediaMetadata;
 class V8MediaSessionActionHandler;
 
@@ -42,7 +43,9 @@ class MODULES_EXPORT MediaSession final
   void setMetadata(MediaMetadata*);
   MediaMetadata* metadata() const;
 
-  void setActionHandler(const String& action, V8MediaSessionActionHandler*);
+  void setActionHandler(const String& action,
+                        V8MediaSessionActionHandler*,
+                        ExceptionState&);
 
   // Called by the MediaMetadata owned by |this| when it has updates. Also used
   // internally when a new MediaMetadata object is set.

third_party/blink/renderer/modules/mediasession/media_session.idl

@@ -30,6 +30,6 @@ callback MediaSessionActionHandler = void ();
     [Measure] attribute MediaMetadata? metadata;
     [Measure] attribute MediaSessionPlaybackState playbackState;
 
-    [Measure] void setActionHandler(MediaSessionAction action,
+    [Measure, RaisesException] void setActionHandler(MediaSessionAction action,
                                     MediaSessionActionHandler? handler);
 };

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -1252,6 +1252,12 @@
       origin_trial_feature_name: "SignatureBasedIntegrity",
       status: "experimental",
     },
+    {
+      name: "SkipAd",
+      depends_on: ["MediaSession"],
+      origin_trial_feature_name: "SkipAd",
+      status: "experimental",
+    },
     {
       name: "SmoothScrollJSIntervention",
       status: "stable",

third_party/blink/web_tests/http/tests/origin_trials/webexposed/skipad-origin-trial.html

+<!DOCTYPE html>
+<meta charset="utf-8">
+<title>SkipAd - media session action exposed by origin trial</title>
+<script src="../../../../resources/testharness.js"></script>
+<script src="../../../../resources/testharnessreport.js"></script>
+<script src="../../../../resources/origin-trials-helper.js"></script>
+
+<script>
+// Can only run this test if SkipAd is not enabled via a Chrome flag.
+// That is only the case when running this in a virtual test suite (by default,
+// runtime enabled features are on for layout tests).
+// To run in virtual test suite:
+// tools/run_web_tests.py virtual/origin-trials-runtimeflags-disabled/http/tests/origin_trials/webexposed
+if (!self.internals.runtimeFlags.skipAdEnabled) {
+  test(t => {
+    assert_throws(new TypeError(), function() {
+      navigator.mediaSession.setActionHandler('skipad', function() {});
+    });
+    assert_throws(new TypeError(), function() {
+      navigator.mediaSession.setActionHandler('skipad', null);
+    });
+  }, 'skipad media session action in Origin-Trial disabled document.');
+}
+
+// generated with command
+// tools/origin_trials/generate_token.py http://127.0.0.1:8000 SkipAd --expire-timestamp=2000000000
+const token = 'AnO+YFdm66rVdQ2ZEckocTP2NIsSxSK8BqyMlgIO/sCbXb484ga4DdbgLOn5z52n6WE9HxpKiB9XI97zDfTGvQoAAABOeyJvcmlnaW4iOiAiaHR0cDovLzEyNy4wLjAuMTo4MDAwIiwgImZlYXR1cmUiOiAiU2tpcEFkIiwgImV4cGlyeSI6IDIwMDAwMDAwMDB9';
+OriginTrialsHelper.add_token(token);
+test(t => {
+  navigator.mediaSession.setActionHandler('skipad', function() {});
+  navigator.mediaSession.setActionHandler('skipad', null);
+}, 'skipad media session action in Origin-Trial enabled document.');
+</script>

tools/metrics/histograms/enums.xml

@@ -21523,6 +21523,7 @@ Called by update_net_error_codes.py.-->
   <int value="2780" label="V8RemotePlayback_WatchAvailability_Method"/>
   <int value="2781" label="V8RemotePlayback_Prompt_Method"/>
   <int value="2782" label="LayoutJankExplicitlyRequested"/>
+  <int value="2783" label="MediaSessionSkipAd"/>
 </enum>
 
 <enum name="FeaturePolicyFeature">