Add SourceBuffer implementations of Audio/VideoTracks

third_party/WebKit/Source/modules/mediasource/SourceBufferAudioTrack.h

Index: third_party/WebKit/Source/modules/mediasource/SourceBufferAudioTrack.h
diff --git a/third_party/WebKit/Source/core/loader/PrerendererClient.h b/third_party/WebKit/Source/modules/mediasource/SourceBufferAudioTrack.h
similarity index 71%
copy from third_party/WebKit/Source/core/loader/PrerendererClient.h
copy to third_party/WebKit/Source/modules/mediasource/SourceBufferAudioTrack.h
index 10bc6cfaa9bce8060ec821da8c08ad011836be32..7938e50d72970af2aec56a0d8c2c4730dfda1452 100644
--- a/third_party/WebKit/Source/core/loader/PrerendererClient.h
+++ b/third_party/WebKit/Source/modules/mediasource/SourceBufferAudioTrack.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2012 Google Inc. All rights reserved.
+ * Copyright (C) 2016 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
@@ -26,34 +26,36 @@
  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
  */
 
-#ifndef PrerendererClient_h
-#define PrerendererClient_h
+#ifndef SourceBufferAudioTrack_h
+#define SourceBufferAudioTrack_h
 
-#include "core/CoreExport.h"
-#include "core/page/Page.h"
 #include "platform/Supplementable.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
-class Page;
-class Prerender;
+class AudioTrack;
+class SourceBuffer;
 
-class CORE_EXPORT PrerendererClient : public WillBeHeapSupplement<Page> {
+class SourceBufferAudioTrack final : public GarbageCollectedFinalized<SourceBufferAudioTrack>, public HeapSupplement<AudioTrack> {

[philipj_slow, 2016/02/23 04:35:07]

Does it need to be finalized?

[servolk, 2016/02/24 00:11:36]

I guess not, so I've changed to a regulat GarbageCollected for now. Although for
some reason the current implementations of regular Audio/VideoTracks are also
GarbageCollectedFinalized, even though they have trivial destructors. Is that
because we want to ensure that we always check that assert in blink ~TrackBase ?

[servolk, 2016/02/24 02:37:15]

Actually, turns out this needs to be finalized, since the PS #7 caused build
failures, so I'm making them finalizable again.

[philipj_slow, 2016/02/26 13:36:54]

The build error was:
In file included from
../../third_party/WebKit/Source/modules/mediasource/AudioTrackSourceBuffer.cpp:5:
../../third_party/WebKit/Source/modules/mediasource/AudioTrackSourceBuffer.h:16:1:
error: [blink-gc] Class 'AudioTrackSourceBuffer' requires finalization.
class AudioTrackSourceBuffer final : public
GarbageCollected<AudioTrackSourceBuffer>, public HeapSupplement<AudioTrack> {
^
../../third_party/WebKit/Source/modules/mediasource/AudioTrackSourceBuffer.cpp:17:1:
note: [blink-gc] User-declared destructor declared here:
AudioTrackSourceBuffer::~AudioTrackSourceBuffer()
^
1 error generated.

If you remote the empty destructor, do you still need finalized?

[servolk, 2016/02/27 01:03:45]

Yes, I tried completely removing the destructor first, that produced a compile
error saying a user-type with non-trivial members must have an explicit
destructor. And after adding an explicit destructor I got this error about
mandatory finalization.

[philipj_slow, 2016/03/02 11:20:44]

I'm sure this is right then, but which are the non-trivial members? If the only
member was a Member<T>, I'd expect that no finalization is required, but maybe
it's something that comes via inheritance, from HeapSupplement<AudioTrack>?

+    USING_GARBAGE_COLLECTED_MIXIN(SourceBufferAudioTrack);
 public:
-    virtual void willAddPrerender(Prerender*) = 0;
+    static SourceBufferAudioTrack& from(AudioTrack&);
+    virtual ~SourceBufferAudioTrack();
+
+    static SourceBuffer* sourceBuffer(AudioTrack&);
 
+    DECLARE_VIRTUAL_TRACE();
+
+private:
     static const char* supplementName();
-    static PrerendererClient* from(Page*);
+    explicit SourceBufferAudioTrack(SourceBuffer*);
 
-protected:
-    PrerendererClient() { }
+    WeakMember<SourceBuffer> m_sourceBuffer;
 };
 
-CORE_EXPORT void providePrerendererClientTo(Page&, PrerendererClient*);
-
 } // namespace blink
 
-#endif // PrerendererClient_h
+#endif