Enable Oilpan by default for webaudio/

Source/modules/webaudio/AudioNode.cpp

Index: Source/modules/webaudio/AudioNode.cpp
diff --git a/Source/modules/webaudio/AudioNode.cpp b/Source/modules/webaudio/AudioNode.cpp
index 733bccb840c23edeca0a71922f2a4f7354d887d0..2860b109329d2c8522f1af83995d4e56b3b91aa0 100644
--- a/Source/modules/webaudio/AudioNode.cpp
+++ b/Source/modules/webaudio/AudioNode.cpp
@@ -53,7 +53,9 @@ AudioNode::AudioNode(AudioContext* context, float sampleRate)
     , m_lastProcessingTime(-1)
     , m_lastNonSilentTime(-1)
 #if !ENABLE(OILPAN)
-    , m_normalRefCount(1) // start out with normal refCount == 1 (like WTF::RefCounted class)
+    // Start with 0, because we use m_normalRefCount only for ref() and deref()
+    // that are explicitly called. Other references are managed by Oilpan.
+    , m_normalRefCount(0)
 #endif
     , m_connectionRefCount(0)
     , m_isDisabled(false)
@@ -63,9 +65,7 @@ AudioNode::AudioNode(AudioContext* context, float sampleRate)
     , m_channelInterpretation(AudioBus::Speakers)
 {
     ScriptWrappable::init(this);
-#if ENABLE(OILPAN)
     m_context->registerLiveNode(*this);
-#endif
 #if DEBUG_AUDIONODE_REFERENCES
     if (!s_isNodeCountInitialized) {
         s_isNodeCountInitialized = true;
@@ -176,7 +176,7 @@ void AudioNode::addInput()
     m_inputs.append(AudioNodeInput::create(*this));
 }
 
-void AudioNode::addOutput(PassOwnPtrWillBeRawPtr<AudioNodeOutput> output)
+void AudioNode::addOutput(AudioNodeOutput* output)
 {
     m_outputs.append(output);
 }
@@ -499,7 +499,13 @@ void AudioNode::disableOutputsIfNecessary()
 #if !ENABLE(OILPAN)
 void AudioNode::ref()
 {
-    atomicIncrement(&m_normalRefCount);
+    // We create a self-keep-alive persistent handle when the first ref()
+    // is called.
+    if (atomicIncrement(&m_normalRefCount) == 1) {
+        ASSERT(!m_keepAlive);
+        m_keepAlive = this;
+    }
+    ASSERT(m_keepAlive);
 
 #if DEBUG_AUDIONODE_REFERENCES
     fprintf(stderr, "%p: %d: AudioNode::ref() %d %d\n", this, nodeType(), m_normalRefCount, m_connectionRefCount);
@@ -544,12 +550,6 @@ void AudioNode::deref()
         ASSERT(context()->isAudioThread());
         context()->addDeferredFinishDeref(this);
     }
-
-    // Once AudioContext::uninitialize() is called there's no more chances for deleteMarkedNodes() to get called, so we call here.
-    // We can't call in AudioContext::~AudioContext() since it will never be called as long as any AudioNode is alive
-    // because AudioNodes keep a reference to the context.
-    if (!context()->isInitialized())
-        context()->deleteMarkedNodes();
 }
 #endif
 
@@ -585,9 +585,6 @@ void AudioNode::breakConnection()
 void AudioNode::breakConnectionWithLock()
 {
     atomicDecrement(&m_connectionRefCount);
-#if !ENABLE(OILPAN)
-    ASSERT(m_normalRefCount > 0);
-#endif
     if (!m_connectionRefCount)
         disableOutputsIfNecessary();
 }
@@ -605,9 +602,9 @@ void AudioNode::finishDeref()
 #endif
 
     if (!m_normalRefCount) {
-        // Mark for deletion at end of each render quantum or when context shuts
-        // down.
-        context()->markForDeletion(this);
+        // This self-keep-alive handle can be resurrected when the ref() is
+        // called again.
+        m_keepAlive = nullptr;
     }
 }
 #endif