Adding an experimental flag to block autoplay with sound in cross-origin iframes

content/child/runtime_features.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/child/runtime_features.h"
 
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/feature_list.h"
@@ skipping 26 matching lines @@
   WebRuntimeFeatures::enableFastMobileScrolling(true);
   WebRuntimeFeatures::enableMediaCapture(true);
   // Android won't be able to reliably support non-persistent notifications, the
   // intended behavior for which is in flux by itself.
   WebRuntimeFeatures::enableNotificationConstructor(false);
   // Android does not yet support switching of audio output devices
   WebRuntimeFeatures::enableAudioOutputDevices(false);
   WebRuntimeFeatures::enableAutoplayMutedVideos(true);
   // Android does not yet support SystemMonitor.
   WebRuntimeFeatures::enableOnDeviceChange(false);
-#else
+#else  // defined(OS_ANDROID)
   WebRuntimeFeatures::enableNavigatorContentUtils(true);
+  if (base::FeatureList::IsEnabled(
+          features::kCrossOriginMediaPlaybackRequiresUserGesture)) {
+    WebRuntimeFeatures::enableAutoplayMutedVideos(true);
+  }
 #endif  // defined(OS_ANDROID)
 
 #if defined(OS_ANDROID) || defined(USE_AURA)
   WebRuntimeFeatures::enableCompositedSelectionUpdate(true);
 #endif
 
 #if !(defined OS_ANDROID || defined OS_CHROMEOS)
     // Only Android, ChromeOS support NetInfo right now.
     WebRuntimeFeatures::enableNetworkInformation(false);
 #endif
@@ skipping 283 matching lines @@
   if (command_line.HasSwitch(switches::kDisableBlinkFeatures)) {
     std::vector<std::string> disabled_features = base::SplitString(
         command_line.GetSwitchValueASCII(switches::kDisableBlinkFeatures),
         ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
     for (const std::string& feature : disabled_features)
       WebRuntimeFeatures::enableFeatureFromString(feature, false);
   }
 }
 
 }  // namespace content