Fix UninitCondition in TrackRunIterator tests.

Fix UninitCondition in TrackRunIterator tests.

UninitCondition
Conditional jump or move depends on uninitialised value(s)
  media::mp4::TrackRunIterator::Init(media::mp4::MovieFragment const&)
    (media/mp4/track_run_iterator.cc:134)
  media::mp4::TrackRunIteratorTest_BasicOperationTest_Test::TestBody()
    (media/mp4/track_run_iterator_unittest.cc:114)
Uninitialised value was created by a stack allocation
  media::mp4::TrackRunIteratorTest::CreateFragment()
    (media/mp4/track_run_iterator_unittest.cc:62)

BUG=none
TEST=media_unittests + valgrind.


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=148284

[DaleCurtis, 2012-07-25 00:42:54]

PTAL. Found while testing next FFmpeg roll. Not sure why the bots didn't pick it
up.

[strobe_, 2012-07-25 00:45:13]

On 2012/07/25 00:42:54, DaleCurtis wrote:
> PTAL. Found while testing next FFmpeg roll. Not sure why the bots didn't pick
it
> up.

LGTM (but you may need a full committer too).

[acolwell GONE FROM CHROMIUM, 2012-07-25 00:55:04]

lgtm

[commit-bot: I haz the power, 2012-07-25 00:58:39]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/dalecurtis@chromium.org/10825005/1

[commit-bot: I haz the power, 2012-07-25 02:36:15]

Change committed as 148284