Oilpan: Move MediaStreamSource, MediaStreamComponent and MediaStreamDescriptor to oilpan's heap

public/platform/WebMediaStreamSource.h

 /*
  * Copyright (C) 2011 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 17 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WebMediaStreamSource_h
 #define WebMediaStreamSource_h
 
 #include "WebCommon.h"
 #include "WebNonCopyable.h"
 #include "WebPrivatePtr.h"
 #include "WebVector.h"
+#if INSIDE_BLINK
+#include "platform/heap/Handle.h"
+#endif
 
 namespace blink {
 
 class MediaStreamSource;
 class WebAudioDestinationConsumer;
 class WebMediaConstraints;
 class WebString;
 
 class WebMediaStreamSource {
 public:
     class ExtraData {
     public:
         ExtraData() : m_owner(0) { }
         virtual ~ExtraData() { }
 
         BLINK_PLATFORM_EXPORT WebMediaStreamSource owner();
 
 #if INSIDE_BLINK
         BLINK_PLATFORM_EXPORT void setOwner(MediaStreamSource*);
 #endif
 
     private:
+#if INSIDE_BLINK
+        GC_PLUGIN_IGNORE("")
+#endif
         MediaStreamSource* m_owner;

[haraken, 2014/08/27 12:33:56]

I'm not sure if I'm doing a right thing here.

- Because ExtraData is a web-exposed class, we cannot make the ExtraData derive
GarbageCollected.

- We cannot use Persistent<MediaStreamSource>, because it can cause a cycle (we
cannot assume nothing about the lifetime of ExtraData objects in the embedder
side).

- If we don't add INSIDE_BLINK, it causes a lot of compile errors.

- Given the above, I used a raw pointer for m_owner.

[zerny-chromium, 2014/08/27 13:21:53]

This raw pointer looks very unsafe, but is no more unsafe than in the non-oilpan
build (given that ExtaData is referenced by an OwnPtr from MediaStreamSource).

[tkent, 2014/09/01 06:59:46]

Resolving this raw pointer needs a lot of work, and I don't think it's worth to
do it now. Let's keep the raw pointer.

[haraken, 2014/09/01 07:10:44]

Thanks, I filed a bug and added the bug number to GC_PLUGIN_IGNORE.

     };
 
     enum Type {
         TypeAudio,
         TypeVideo
     };
 
     enum ReadyState {
         ReadyStateLive = 0,
         ReadyStateMuted = 1,
@@ skipping 33 matching lines @@
     BLINK_PLATFORM_EXPORT WebMediaConstraints constraints();
 
     // Only used if if this is a WebAudio source.
     // The WebAudioDestinationConsumer is not owned, and has to be disposed of separately
     // after calling removeAudioConsumer.
     BLINK_PLATFORM_EXPORT bool requiresAudioConsumer() const;
     BLINK_PLATFORM_EXPORT void addAudioConsumer(WebAudioDestinationConsumer*);
     BLINK_PLATFORM_EXPORT bool removeAudioConsumer(WebAudioDestinationConsumer*);
 
 #if INSIDE_BLINK
-    BLINK_PLATFORM_EXPORT WebMediaStreamSource(const WTF::PassRefPtr<MediaStreamSource>&);
+    BLINK_PLATFORM_EXPORT WebMediaStreamSource(MediaStreamSource*);
     BLINK_PLATFORM_EXPORT WebMediaStreamSource& operator=(MediaStreamSource*);
-    BLINK_PLATFORM_EXPORT operator WTF::PassRefPtr<MediaStreamSource>() const;
     BLINK_PLATFORM_EXPORT operator MediaStreamSource*() const;
 #endif
 
 private:
     WebPrivatePtr<MediaStreamSource> m_private;
 };
 
 } // namespace blink
 
 #endif // WebMediaStreamSource_h