Fix sourceAbort() for BMFF streams.

Fix sourceAbort() for BMFF streams.

MP4StreamParser::Flush() (called eventually by sourceAbort()) did not reset the
parser state, and so would only work if the call happened to come when the
parser was already in a particular state (which happened to always be true for
the browser test harness it was originally tested with).

Additionally, the format-specific buffer conversion methods did not cause
an error to be propagated to the caller on failure, resulting in unexpected
success for the added test.

BUG=
TEST=MP4StreamParserTest.TestFlush


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=149730

[acolwell GONE FROM CHROMIUM, 2012-08-02 20:23:47]

LGTM

[commit-bot: I haz the power, 2012-08-02 21:39:02]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/strobe@google.com/10843044/1

[commit-bot: I haz the power, 2012-08-02 22:54:36]

Change committed as 149730