Fix incomplete teardown of demuxer.

Fix incomplete teardown of demuxer.

I ran into an issue with PipelineIntegrationTests where one of the
security videos was causing ~FileDataSource to DCHECK complain about
file_ never being torn down.

Tracing this back, it's because we return NULL for the demuxer when
an error is encountered. This prevents demuxer->Stop() from being called
which leaves the data source in an unhappy state.

BUG=none
TEST=PipelineIntegrationTests/media_unittests


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=120730

[DaleCurtis, 2012-02-07 00:34:46]

PTAL. Not sure if this is the right fix, locally it lets me move forward on my
ffmpeg security testing.

https://chromiumcodereview.appspot.com/9350004/diff/1/media/base/pipeline.cc
File media/base/pipeline.cc (right):

https://chromiumcodereview.appspot.com/9350004/diff/1/media/base/pipeline.cc#...
media/base/pipeline.cc:1146: if (!demuxer) {
This can probably never be reached now.

[scherkus (not reviewing), 2012-02-07 00:41:16]

LGTM w/ one suggestion

https://chromiumcodereview.appspot.com/9350004/diff/1/media/base/pipeline.cc
File media/base/pipeline.cc (right):

https://chromiumcodereview.appspot.com/9350004/diff/1/media/base/pipeline.cc#...
media/base/pipeline.cc:1146: if (!demuxer) {
On 2012/02/07 00:34:46, DaleCurtis wrote:
> This can probably never be reached now.

CHECK() it

longer term demuxer factories should go away so we'll always have a valid
reference and at that point Pipeline will inspect the status result of
Initialize()

[DaleCurtis, 2012-02-07 03:20:55]

https://chromiumcodereview.appspot.com/9350004/diff/1/media/base/pipeline.cc
File media/base/pipeline.cc (right):

https://chromiumcodereview.appspot.com/9350004/diff/1/media/base/pipeline.cc#...
media/base/pipeline.cc:1146: if (!demuxer) {
On 2012/02/07 00:41:16, scherkus wrote:
> On 2012/02/07 00:34:46, DaleCurtis wrote:
> > This can probably never be reached now.
> 
> CHECK() it
> 
> longer term demuxer factories should go away so we'll always have a valid
> reference and at that point Pipeline will inspect the status result of
> Initialize()

Done.

[commit-bot: I haz the power, 2012-02-07 03:23:52]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dalecurtis@chromium.org/9350004/4001

[commit-bot: I haz the power, 2012-02-07 06:45:57]

Change committed as 120730