AudioBufferSourceNode.buffer can only be set once.

Source/modules/webaudio/AudioBufferSourceNode.cpp

Index: Source/modules/webaudio/AudioBufferSourceNode.cpp
diff --git a/Source/modules/webaudio/AudioBufferSourceNode.cpp b/Source/modules/webaudio/AudioBufferSourceNode.cpp
index 77d37af96f0cd98dec176ddae49a51558765e494..714eb9f0385e3cfb70a1a5c7d37973837bd451e9 100644
--- a/Source/modules/webaudio/AudioBufferSourceNode.cpp
+++ b/Source/modules/webaudio/AudioBufferSourceNode.cpp
@@ -340,6 +340,13 @@ void AudioBufferSourceNode::setBuffer(AudioBuffer* buffer, ExceptionState& excep
 {
     ASSERT(isMainThread());
 
+    if (m_buffer) {
+        exceptionState.throwDOMException(
+            InvalidStateError,
+            "buffer can only be set once.");

[hongchan, 2015/01/16 23:42:09]

Perhaps the first word should be capitalized? Other places in chromium code base
are throwing properly capitalized message when it is a complete sentence.

WDYT?

[Raymond Toy, 2015/01/17 00:03:16]

Will do. And get rid of the trailing period.

[Raymond Toy, 2015/01/20 18:06:00]

Done.

+        return;
+    }
+
     // The context must be locked since changing the buffer can re-configure the number of channels that are output.
     AudioContext::AutoLocker contextLocker(context());