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.


Review URL: https://chromiumcodereview.appspot.com/10825005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@148284 0039d316-1c4b-4281-b951-d872f2087c98

media/mp4/track_run_iterator_unittest.cc

@@ -66,6 +66,7 @@ class TrackRunIteratorTest : public testing::Test {
     moof.tracks[0].header.has_default_sample_flags = true;
     moof.tracks[0].header.default_sample_duration = 1024;
     moof.tracks[0].header.default_sample_size = 4;
+    moof.tracks[0].header.sample_description_index = 0;
     moof.tracks[0].runs.resize(2);
     moof.tracks[0].runs[0].sample_count = 10;
     moof.tracks[0].runs[0].data_offset = 100;
@@ -76,6 +77,7 @@ class TrackRunIteratorTest : public testing::Test {
 
     moof.tracks[1].header.track_id = 2;
     moof.tracks[1].header.has_default_sample_flags = false;
+    moof.tracks[1].header.sample_description_index = 0;
     moof.tracks[1].decode_time.decode_time = 10;
     moof.tracks[1].runs.resize(1);
     moof.tracks[1].runs[0].sample_count = 10;