Web Audio: when media playback requires a user gesture, apply rule to cross origin iframes.

third_party/WebKit/Source/modules/webaudio/AudioScheduledSourceNode.cpp

 /*
  * Copyright (C) 2012, 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:
  * 1.  Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 114 matching lines @@
         finish();
     }
 
     return;
 }
 
 void AudioScheduledSourceHandler::start(double when, ExceptionState& exceptionState)
 {
     DCHECK(isMainThread());
 
-    context()->recordUserGestureState();
+    // TODO(mlamouri): record when this is called with a user gesture and could
+    // have started the AudioContext if following Safari iOS rules.
 
     if (playbackState() != UNSCHEDULED_STATE) {
         exceptionState.throwDOMException(
             InvalidStateError,
             "cannot call start more than once.");
         return;
     }
 
     if (when < 0) {
         exceptionState.throwDOMException(
@@ skipping 126 matching lines @@
     // playback state if the context is closed.
     if (context()->isContextClosed())
         return false;
 
     // If a node is scheduled or playing, do not collect the node prematurely
     // even its reference is out of scope. Then fire onended event if assigned.
     return audioScheduledSourceHandler().isPlayingOrScheduled();
 }
 
 } // namespace blink