MediaElementAudioSourceNode::dispose() should call...

MediaElementAudioSourceNode::dispose() should call HTMLMediaElement::setAudioSourceNode(0) in oilpan builds

Currently HTMLMediaElement::setAudioSourceNode(0) is called only in non-oilpan builds.
However, there is no reason why oilpan builds cannot call HTMLMediaElement::setAudioSourceNode(0).
It's better to call it both in oilpan builds and non-oilpan builds and reduce #if branches.

BUG=340522

Review URL: https://codereview.chromium.org/456273002

git-svn-id: svn://svn.chromium.org/blink/trunk@179939 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/Source/core/html/HTMLMediaElement.cpp

@@ -459,9 +459,11 @@ HTMLMediaElement::~HTMLMediaElement()
     m_isFinalizing = true;
 #endif
 
-    // The m_audioSourceNode is either dead already or it is dying together with
-    // this HTMLMediaElement which it strongly keeps alive.
-#if ENABLE(WEB_AUDIO) && !ENABLE(OILPAN)
+    // m_audioSourceNode is explicitly cleared by AudioNode::dispose().
+    // Since AudioNode::dispose() is guaranteed to be always called before
+    // the AudioNode is destructed, m_audioSourceNode is explicitly cleared
+    // even if the AudioNode and the HTMLMediaElement die together.
+#if ENABLE(WEB_AUDIO)
     ASSERT(!m_audioSourceNode);
 #endif
     clearMediaPlayerAndAudioSourceProviderClientWithoutLocking();

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

@@ -69,9 +69,7 @@ MediaElementAudioSourceNode::~MediaElementAudioSourceNode()
 
 void MediaElementAudioSourceNode::dispose()
 {
-#if !ENABLE(OILPAN)
     m_mediaElement->setAudioSourceNode(0);
-#endif
     uninitialize();
     AudioSourceNode::dispose();
 }