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

content/renderer/render_view_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/renderer/render_view_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <memory>
 
@@ skipping 1113 matching lines @@
   settings->setClobberUserAgentInitialScaleQuirk(
       prefs.clobber_user_agent_initial_scale_quirk);
   settings->setIgnoreMainFrameOverflowHiddenQuirk(
       prefs.ignore_main_frame_overflow_hidden_quirk);
   settings->setReportScreenSizeInPhysicalPixelsQuirk(
       prefs.report_screen_size_in_physical_pixels_quirk);
   settings->setShouldReuseGlobalForUnownedMainFrame(
       prefs.resue_global_for_unowned_main_frame);
   settings->setPreferHiddenVolumeControls(true);
   settings->setShrinksViewportContentToFit(true);
+  WebRuntimeFeatures::enableAutoplayMutedVideos(
+      prefs.autoplay_muted_videos_enabled);
 #endif
 
   settings->setAutoplayExperimentMode(
       blink::WebString::fromUTF8(prefs.autoplay_experiment_mode));
 
   settings->setViewportEnabled(prefs.viewport_enabled);
   settings->setViewportMetaEnabled(prefs.viewport_meta_enabled);
   settings->setViewportStyle(
       static_cast<blink::WebViewportStyle>(prefs.viewport_style));
 
@@ skipping 2251 matching lines @@
         return render_frame->focused_pepper_plugin();
     }
     frame = frame->traverseNext(false);
   }
 
   return nullptr;
 }
 #endif
 
 }  // namespace content