Oilpan: eagerly sweep some mediasource and mediastream objects.

Oilpan: eagerly sweep some mediasource and mediastream objects.

The following objects provide a 'client' notification interface to
bridge objects that they themselves own or refer to:

 - SourceBuffer (WebSourceBuffer, WebSourceBufferClient)
 - MediaStream (MediaStreamDescriptor, MediaStreamDescriptorClient)
 - MediaStreamTrack (MediaStreamSource, MediaStreamSource::Observer)
 - RTCDTMFSender (WebRTCDTMFSenderHandler, WebRTCDTMFSenderHandlerClient)
 - RTCDataChannel (WebRTCDataChannelHandler, WebRTCDataChannelHandlerClient)
 - RTCPeerConnection (WebRTCPeerConnectionHandler,
                      WebRTCPeerConnectionHandlerClient)

The name of the bridge object and client given in parens. The bridge
objects allow the embedder to notify the 'client'.

To make these safe wrt Oilpan lazy sweeping (see associated bug for details
on why this is required), add annotations to the class declarations for
the objects affected.

While some of these objects are ActiveDOMObjects and will in most cases
be explicitly stopped as part of detachment, where their overridden stop()
methods will in some cases clear out the client (or bridge) object, this
is a delicate dependency. Insisting on eager sweeping & finalization
makes their embedder detachment safe, regardless.

R=haraken
BUG=491488
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=196469

[sof, 2015-05-24 06:51:30]

sigbjornf@opera.com changed reviewers:
+ oilpan-reviews@chromium.org

[sof, 2015-05-24 06:51:31]

please take a look.

[haraken, 2015-05-25 00:20:16]

Ping me once you land the EAGERLY_FINALIZED().

[sof, 2015-06-03 15:14:40]

On 2015/05/25 00:20:16, haraken wrote:
> Ping me once you land the EAGERLY_FINALIZED().

Now updated (but GC plugin support needs to be in place before moving ahead on
some of these.)

[haraken, 2015-06-04 01:06:55]

haraken@chromium.org changed reviewers:
+ haraken@chromium.org

[haraken, 2015-06-04 01:06:56]

LGTM

https://codereview.chromium.org/1149293003/diff/20001/Source/modules/mediastr...
File Source/modules/mediastream/MediaStreamTrack.h (right):

https://codereview.chromium.org/1149293003/diff/20001/Source/modules/mediastr...
Source/modules/mediastream/MediaStreamTrack.h:91: // Oilpan: need to eagerly
unregister as observer.

FYI, this should be fixed by https://codereview.chromium.org/552653005. The CL
was reverted and I didn't have a bandwidth to rework on it...

[sof, 2015-06-04 06:18:03]

https://codereview.chromium.org/1149293003/diff/20001/Source/modules/mediastr...
File Source/modules/mediastream/MediaStreamTrack.h (right):

https://codereview.chromium.org/1149293003/diff/20001/Source/modules/mediastr...
Source/modules/mediastream/MediaStreamTrack.h:91: // Oilpan: need to eagerly
unregister as observer.
On 2015/06/04 01:06:56, haraken wrote:
> 
> FYI, this should be fixed by https://codereview.chromium.org/552653005. The CL
> was reverted and I didn't have a bandwidth to rework on it...

I'd completely forgotten about that effort.. I created
https://code.google.com/p/chromium/issues/detail?id=496535 so as to not to lose
track of it.

[sof, 2015-06-04 06:18:18]

The CQ bit was checked by sigbjornf@opera.com

[commit-bot: I haz the power, 2015-06-04 06:18:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1149293003/20001

[commit-bot: I haz the power, 2015-06-04 06:59:28]

Committed patchset #2 (id:20001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=196469