Add SourceBuffer implementations of Audio/VideoTracks

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

 /*
- * 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
  * 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
  * copyright notice, this list of conditions and the following disclaimer
  * in the documentation and/or other materials provided with the
  * distribution.
  *     * Neither the name of Google Inc. nor the names of its
  * contributors may be used to endorse or promote products derived from
  * this software without specific prior written permission.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  * 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