Pull AudioDestinationConsumer off the Blink GC heap.

The AudioDestinationConsumer interface and its single implementation
does not meet the bar for being on the Blink GC heap. It doesn't cause
harm to have them there, but in order to diagnose an unexplained
failure, pull these objects off the heap.

We may want to restore them to the Blink GC heap once the issue has
been resolved.

R=
BUG=682945

Review-Url: https://codereview.chromium.org/2748133003
Cr-Commit-Position: refs/heads/master@{#456736}

third_party/WebKit/Source/platform/audio/AudioDestinationConsumer.h

@@ -31,20 +31,17 @@
 #ifndef AudioDestinationConsumer_h
 #define AudioDestinationConsumer_h
 
+#include <memory>
 #include "platform/PlatformExport.h"
-#include "platform/heap/Handle.h"
 
 namespace blink {
 
 class AudioBus;
 
-class PLATFORM_EXPORT AudioDestinationConsumer
-    : public GarbageCollected<AudioDestinationConsumer> {
+class PLATFORM_EXPORT AudioDestinationConsumer {
  public:
   virtual void setFormat(size_t numberOfChannels, float sampleRate) = 0;
   virtual void consumeAudio(AudioBus*, size_t numberOfFrames) = 0;
-
-  DEFINE_INLINE_VIRTUAL_TRACE() {}
 };
 
 }  // namespace blink

third_party/WebKit/Source/platform/exported/WebMediaStreamSource.cpp

@@ -148,6 +148,8 @@ bool WebMediaStreamSource::requiresAudioConsumer() const {
 }
 
 class ConsumerWrapper final : public AudioDestinationConsumer {
+  USING_FAST_MALLOC(ConsumerWrapper);
+
  public:
   static ConsumerWrapper* create(WebAudioDestinationConsumer* consumer) {
     return new ConsumerWrapper(consumer);
@@ -196,12 +198,10 @@ bool WebMediaStreamSource::removeAudioConsumer(
   ASSERT(isMainThread());
   ASSERT(!m_private.isNull() && consumer);
 
-  const HeapHashSet<Member<AudioDestinationConsumer>>& consumers =
+  const HashSet<AudioDestinationConsumer*>& consumers =
       m_private->audioConsumers();
-  for (HeapHashSet<Member<AudioDestinationConsumer>>::const_iterator it =
-           consumers.begin();
-       it != consumers.end(); ++it) {
-    ConsumerWrapper* wrapper = static_cast<ConsumerWrapper*>(it->get());
+  for (AudioDestinationConsumer* it : consumers) {
+    ConsumerWrapper* wrapper = static_cast<ConsumerWrapper*>(it);
     if (wrapper->consumer() == consumer) {
       m_private->removeAudioConsumer(wrapper);
       return true;

third_party/WebKit/Source/platform/mediastream/MediaStreamSource.cpp

@@ -85,8 +85,7 @@ bool MediaStreamSource::removeAudioConsumer(
     AudioDestinationConsumer* consumer) {
   ASSERT(m_requiresConsumer);
   MutexLocker locker(m_audioConsumersLock);
-  HeapHashSet<Member<AudioDestinationConsumer>>::iterator it =
-      m_audioConsumers.find(consumer);
+  auto it = m_audioConsumers.find(consumer);
   if (it == m_audioConsumers.end())
     return false;
   m_audioConsumers.erase(it);
@@ -101,24 +100,19 @@ void MediaStreamSource::setAudioFormat(size_t numberOfChannels,
                                        float sampleRate) {
   ASSERT(m_requiresConsumer);
   MutexLocker locker(m_audioConsumersLock);
-  for (HeapHashSet<Member<AudioDestinationConsumer>>::iterator it =
-           m_audioConsumers.begin();
-       it != m_audioConsumers.end(); ++it)
-    (*it)->setFormat(numberOfChannels, sampleRate);
+  for (AudioDestinationConsumer* consumer : m_audioConsumers)
+    consumer->setFormat(numberOfChannels, sampleRate);
 }
 
 void MediaStreamSource::consumeAudio(AudioBus* bus, size_t numberOfFrames) {
   ASSERT(m_requiresConsumer);
   MutexLocker locker(m_audioConsumersLock);
-  for (HeapHashSet<Member<AudioDestinationConsumer>>::iterator it =
-           m_audioConsumers.begin();
-       it != m_audioConsumers.end(); ++it)
-    (*it)->consumeAudio(bus, numberOfFrames);
+  for (AudioDestinationConsumer* consumer : m_audioConsumers)
+    consumer->consumeAudio(bus, numberOfFrames);
 }
 
 DEFINE_TRACE(MediaStreamSource) {
   visitor->trace(m_observers);
-  visitor->trace(m_audioConsumers);
 }
 
 }  // namespace blink

third_party/WebKit/Source/platform/mediastream/MediaStreamSource.h

@@ -102,7 +102,7 @@ class PLATFORM_EXPORT MediaStreamSource final
   bool requiresAudioConsumer() const { return m_requiresConsumer; }
   void addAudioConsumer(AudioDestinationConsumer*);
   bool removeAudioConsumer(AudioDestinationConsumer*);
-  const HeapHashSet<Member<AudioDestinationConsumer>>& audioConsumers() {
+  const HashSet<AudioDestinationConsumer*>& audioConsumers() {
     return m_audioConsumers;
   }
 
@@ -126,7 +126,7 @@ class PLATFORM_EXPORT MediaStreamSource final
   bool m_requiresConsumer;
   HeapHashSet<WeakMember<Observer>> m_observers;
   Mutex m_audioConsumersLock;
-  HeapHashSet<Member<AudioDestinationConsumer>> m_audioConsumers;
+  HashSet<AudioDestinationConsumer*> m_audioConsumers;
   std::unique_ptr<ExtraData> m_extraData;
   WebMediaConstraints m_constraints;
 };