WebAudio: record whether user gesture was available and provided.

third_party/WebKit/Source/modules/webaudio/AbstractAudioContext.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 243 matching lines @@
     //  - closeContext() has been called.
     //  - 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 recordUserGesture();
+
 protected:
     explicit AbstractAudioContext(Document*);
     AbstractAudioContext(Document*, unsigned numberOfChannels, size_t numberOfFrames, float sampleRate);
 
     void initialize();
     void uninitialize();
 
     void setContextState(AudioContextState);
 
     virtual void didClose() {}
@@ skipping 55 matching lines @@
     void resolvePromisesForResumeOnMainThread();
 
     // When the context is going away, reject any pending script promise resolvers.
     virtual void rejectPendingResolvers();
 
     // True if we're in the process of resolving promises for resume().  Resolving can take some
     // time and the audio context process loop is very fast, so we don't want to call resolve an
     // excessive number of times.
     bool m_isResolvingResumePromises;
 
+    // Whether a user gesture is required to start this AudioContext.
+    bool m_userGestureRequired;
+
     unsigned m_connectionCount;
 
     // Graph locking.
     RefPtr<DeferredTaskHandler> m_deferredTaskHandler;
 
     // The state of the AbstractAudioContext.
     AudioContextState m_contextState;
 
     AsyncAudioDecoder m_audioDecoder;
 
@@ skipping 15 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 // AbstractAudioContext_h