Media Controls: make the MediaControlsOverlayPlayButton a runtime enabled flag.

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 1007 matching lines @@
 
 #if defined(OS_ANDROID)
   settings->setAllowCustomScrollbarInMainFrame(false);
   settings->setTextAutosizingEnabled(prefs.text_autosizing_enabled);
   settings->setAccessibilityFontScaleFactor(prefs.font_scale_factor);
   settings->setDeviceScaleAdjustment(prefs.device_scale_adjustment);
   settings->setFullscreenSupported(prefs.fullscreen_supported);
   web_view->setIgnoreViewportTagScaleLimits(prefs.force_enable_zoom);
   settings->setAutoZoomFocusedNodeToLegibleScale(true);
   settings->setDoubleTapToZoomEnabled(prefs.double_tap_to_zoom_enabled);
-  settings->setMediaControlsOverlayPlayButtonEnabled(true);
   settings->setMediaPlaybackRequiresUserGesture(
       prefs.user_gesture_required_for_media_playback);
   settings->setMediaPlaybackGestureWhitelistScope(
       blink::WebString::fromUTF8(prefs.media_playback_gesture_whitelist_scope));
   settings->setDefaultVideoPosterURL(
       WebString::fromASCII(prefs.default_video_poster_url.spec()));
   settings->setSupportDeprecatedTargetDensityDPI(
       prefs.support_deprecated_target_density_dpi);
   settings->setUseLegacyBackgroundSizeShorthandBehavior(
       prefs.use_legacy_background_size_shorthand_behavior);
@@ skipping 1680 matching lines @@
                             INPUT_EVENT_ACK_STATE_NOT_CONSUMED);
   }
 
   std::unique_ptr<InputEventAck> ack(
       new InputEventAck(InputEventAckSource::MAIN_THREAD, input_event->type(),
                         INPUT_EVENT_ACK_STATE_NOT_CONSUMED));
   OnInputEventAck(std::move(ack));
 }
 
 }  // namespace content