[Android] Added a runtime flag to enable autoplay of muted videos.

content/browser/renderer_host/render_view_host_impl.cc

 // Copyright (c) 2012 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/browser/renderer_host/render_view_host_impl.h"
 
 #include <set>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 410 matching lines @@
 
 #if defined(OS_ANDROID)
   // On Android, user gestures are normally required, unless that requirement
   // is disabled with a command-line switch or the equivalent field trial is
   // is set to "Enabled".
   const std::string autoplay_group_name = base::FieldTrialList::FindFullName(
       "MediaElementAutoplay");
   prefs.user_gesture_required_for_media_playback = !command_line.HasSwitch(
       switches::kDisableGestureRequirementForMediaPlayback) &&
           (autoplay_group_name.empty() || autoplay_group_name != "Enabled");
+  prefs.autoplay_muted_videos_enabled = command_line.HasSwitch(
+      switches::kEnableAutoplayMutedVideos);
 #endif
 
   // Handle autoplay gesture override experiment.
   // Note that anything but a well-formed string turns the experiment off.
   prefs.autoplay_experiment_mode = base::FieldTrialList::FindFullName(
       "MediaElementGestureOverrideExperiment");
 
   prefs.touch_enabled = ui::AreTouchEventsEnabled();
   prefs.device_supports_touch = prefs.touch_enabled &&
       ui::GetTouchScreensAvailability() ==
@@ skipping 880 matching lines @@
   } else {
     render_view_ready_on_process_launch_ = true;
   }
 }
 
 void RenderViewHostImpl::RenderViewReady() {
   delegate_->RenderViewReady(this);
 }
 
 }  // namespace content