Fix a crash caused by track insertion after load().

Fix a crash caused by track insertion after load().

This patch fixes a crash caused by stale LoadMediaResource flag in
m_pendingActionFlags when load() is explicitly called on a media
element. The insertion of a <track> element triggers the crash by
triggering the scheduling of the m_loadTimer, which ends up using the
stale flag data when the timer fires. The fix is to clear the
LoadMediaResource flag from m_pendingActionFlags when a new load is
initiated.

BUG=356352
TEST=LayoutTests/media/track/track-insert-after-load-crash.html

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=170003

[acolwell GONE FROM CHROMIUM, 2014-03-26 01:13:30]

https://codereview.chromium.org/211373009/diff/1/Source/core/html/HTMLMediaEl...
File Source/core/html/HTMLMediaElement.cpp (right):

https://codereview.chromium.org/211373009/diff/1/Source/core/html/HTMLMediaEl...
Source/core/html/HTMLMediaElement.cpp:609: // FIXME: Figure out appropriate
place to reset LoadTextTrackResource if necessary and set m_pendingActionFlags
to 0 here.
I will fix this in a follow-up CL since making this 0 now caused many TextTrack
tests to fail and I think fixing in this CL would cloud the main crashing
problem I'm trying to address.

[adamk, 2014-03-26 01:25:26]

lgtm

[acolwell GONE FROM CHROMIUM, 2014-03-26 01:28:32]

The CQ bit was checked by acolwell@chromium.org

[commit-bot: I haz the power, 2014-03-26 01:28:36]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/acolwell@chromium.org/211373009/1

[commit-bot: I haz the power, 2014-03-26 02:14:43]

Change committed as 170003