Add download button to MediaDocument on Android.

third_party/WebKit/Source/web/WebRuntimeFeatures.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 117 matching lines @@
 void WebRuntimeFeatures::enableImageColorProfiles(bool enable)
 {
     RuntimeEnabledFeatures::setImageColorProfilesEnabled(enable);
 }
 
 void WebRuntimeFeatures::enableMediaCapture(bool enable)
 {
     RuntimeEnabledFeatures::setMediaCaptureEnabled(enable);
 }
 
+void WebRuntimeFeatures::enableMediaDocumentDownloadButton(bool enable)
+{
+    RuntimeEnabledFeatures::setMediaDocumentDownloadButtonEnabled(enable);
+}
+
 void WebRuntimeFeatures::enableMediaRecorder(bool enable)
 {
     RuntimeEnabledFeatures::setMediaRecorderEnabled(enable);
 }
 
 void WebRuntimeFeatures::enableNotificationActionIcons(bool enable)
 {
     RuntimeEnabledFeatures::setNotificationActionIconsEnabled(enable);
 }
 
@@ skipping 156 matching lines @@
 {
     RuntimeEnabledFeatures::setRenderingPipelineThrottlingEnabled(enable);
 }
 
 bool WebRuntimeFeatures::isServiceWorkerExtendableMessageEventEnabled()
 {
     return RuntimeEnabledFeatures::serviceWorkerExtendableMessageEventEnabled();
 }
 
 } // namespace blink