Fix race when HTMLMediaElement.play() is called just after pause().

Fix race when HTMLMediaElement.play() is called just after pause().

The consequence is that the Promise returned by play() is rejected by
the task created by pause(). The fix is to associate the tasks with a
list of promises.

BUG=593273
TBR=avayvod@chromium.org

Review-Url: https://codereview.chromium.org/1865933002
Cr-Commit-Position: refs/heads/master@{#398370}
(cherry picked from commit 3a82d82079ca79cddd932eb77f924db5428885b9)

Committed: https://chromium.googlesource.com/chromium/src/+/b62b49b650018c1367069a6c8e2a049e998fc4d9

[mlamouri (slow - plz ping), 2016-06-10 10:34:09]

Description was changed from

==========
Fix race when HTMLMediaElement.play() is called just after pause().

The consequence is that the Promise returned by play() is rejected by
the task created by pause(). The fix is to associate the tasks with a
list of promises.

BUG=593273

Review-Url: https://codereview.chromium.org/1865933002
Cr-Commit-Position: refs/heads/master@{#398370}
(cherry picked from commit 3a82d82079ca79cddd932eb77f924db5428885b9)
==========

to

==========
Fix race when HTMLMediaElement.play() is called just after pause().

The consequence is that the Promise returned by play() is rejected by
the task created by pause(). The fix is to associate the tasks with a
list of promises.

BUG=593273
TBR=avayvod@chromium.org

Review-Url: https://codereview.chromium.org/1865933002
Cr-Commit-Position: refs/heads/master@{#398370}
(cherry picked from commit 3a82d82079ca79cddd932eb77f924db5428885b9)
==========

[mlamouri (slow - plz ping), 2016-06-10 10:36:52]

Description was changed from

==========
Fix race when HTMLMediaElement.play() is called just after pause().

The consequence is that the Promise returned by play() is rejected by
the task created by pause(). The fix is to associate the tasks with a
list of promises.

BUG=593273
TBR=avayvod@chromium.org

Review-Url: https://codereview.chromium.org/1865933002
Cr-Commit-Position: refs/heads/master@{#398370}
(cherry picked from commit 3a82d82079ca79cddd932eb77f924db5428885b9)
==========

to

==========
Fix race when HTMLMediaElement.play() is called just after pause().

The consequence is that the Promise returned by play() is rejected by
the task created by pause(). The fix is to associate the tasks with a
list of promises.

BUG=593273
TBR=avayvod@chromium.org

Review-Url: https://codereview.chromium.org/1865933002
Cr-Commit-Position: refs/heads/master@{#398370}
(cherry picked from commit 3a82d82079ca79cddd932eb77f924db5428885b9)

Committed:
https://chromium.googlesource.com/chromium/src/+/b62b49b650018c1367069a6c8e2a...
==========

[mlamouri (slow - plz ping), 2016-06-10 10:36:53]

Committed patchset #1 (id:1) manually as
b62b49b650018c1367069a6c8e2a049e998fc4d9 (presubmit successful).