WebAudio: record whether user gesture was available and provided.

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

 /*
  * 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 423 matching lines @@
 
 void AudioBufferSourceHandler::start(double when, double grainOffset, double grainDuration, ExceptionState& exceptionState)
 {
     startSource(when, grainOffset, grainDuration, true, exceptionState);
 }
 
 void AudioBufferSourceHandler::startSource(double when, double grainOffset, double grainDuration, bool isDurationGiven, ExceptionState& exceptionState)
 {
     ASSERT(isMainThread());
 
+    context()->recordUserGestureState();

[Raymond Toy, 2016/06/06 15:10:08]

Probably want this after all of the code that could throw exceptions.

[mlamouri (slow - plz ping), 2016/06/06 16:14:13]

WebKit puts it exactly here actually :(

+
     if (playbackState() != UNSCHEDULED_STATE) {
         exceptionState.throwDOMException(
             InvalidStateError,
             "cannot call start more than once.");
         return;
     }
 
     if (when < 0) {
         exceptionState.throwDOMException(
             InvalidStateError,
@@ skipping 227 matching lines @@
 {
     audioBufferSourceHandler().start(when, grainOffset, exceptionState);
 }
 
 void AudioBufferSourceNode::start(double when, double grainOffset, double grainDuration, ExceptionState& exceptionState)
 {
     audioBufferSourceHandler().start(when, grainOffset, grainDuration, exceptionState);
 }
 
 } // namespace blink