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

third_party/WebKit/Source/modules/webaudio/BaseAudioContext.h

 /*
  * Copyright (C) 2010, 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 244 matching lines @@
     //  - it has been stopped by its execution context.
     virtual bool isContextClosed() const { return m_isCleared; }
 
     // Get the security origin for this audio context.
     SecurityOrigin* getSecurityOrigin() const;
 
     // Get the PeriodicWave for the specified oscillator type.  The table is initialized internally
     // if necessary.
     PeriodicWave* periodicWave(int type);
 
-    // Check whether the AudioContext requires a user gesture and whether the
-    // current stack is processing user gesture and record these information in
-    // a histogram.
-    void recordUserGestureState();
+    // Called by AudioContext nodes to start the AudioContext when it is
+    // suspended because of gesture requirement.
+    // It will be a no-op if:
+    // - no user gesture is required, or
+    // - a user gesture is required but none was provided.
+    void startRenderingIfNeeded();
 
 protected:
     explicit BaseAudioContext(Document*);
     BaseAudioContext(Document*, unsigned numberOfChannels, size_t numberOfFrames, float sampleRate);
 
     void initialize();
     void uninitialize();
 
     void setContextState(AudioContextState);
 
@@ skipping 94 matching lines @@
     Member<PeriodicWave> m_periodicWaveTriangle;
 
     // This is considering 32 is large enough for multiple channels audio.
     // It is somewhat arbitrary and could be increased if necessary.
     enum { MaxNumberOfChannels = 32 };
 };
 
 } // namespace blink
 
 #endif // BaseAudioContext_h