Fixing a crash in MediaCustomControlsFullscreenDetector when the page is destroyed

Fixing a crash in MediaCustomControlsFullscreenDetector when the page is destroyed

There's a situation that hits a DCHECK() in
MediaCustomControlsFullscreenDetector when the video become
fullscreen but the page navigates away before the timer fires.
This CL solves the issue by stopping the timer when the
ExecutionContext is destroyed.

This CL also moves the common parts of MockWebMediaPlayer into
EmptyWebMediaPlayer. There are still some other
MockWebMediaPlayers which will be adopted in a follow-up.

BUG=698034
Review-Url: https://codereview.chromium.org/2729613007
Cr-Commit-Position: refs/heads/master@{#455740}
(cherry picked from commit fe180eb4effd53064142647a839b89d3910dfff0)

Review-Url: https://codereview.chromium.org/2747633002 .
Cr-Commit-Position: refs/branch-heads/3029@{#136}
Cr-Branched-From: 939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed: https://chromium.googlesource.com/chromium/src/+/7bb43d450f514993aa48475c759af3a072fa6038

[Zhiqiang Zhang (Slow), 2017-03-12 18:34:31]

Description was changed from

==========
Fixing a crash in MediaCustomControlsFullscreenDetector when the page is
destroyed

There's a situation that hits a DCHECK() in
MediaCustomControlsFullscreenDetector when the video become
fullscreen but the page navigates away before the timer fires.
This CL solves the issue by stopping the timer when the
ExecutionContext is destroyed.

This CL also moves the common parts of MockWebMediaPlayer into
EmptyWebMediaPlayer. There are still some other
MockWebMediaPlayers which will be adopted in a follow-up.

BUG=698034

Review-Url: https://codereview.chromium.org/2729613007
Cr-Commit-Position: refs/heads/master@{#455740}
(cherry picked from commit fe180eb4effd53064142647a839b89d3910dfff0)
==========

to

==========
Fixing a crash in MediaCustomControlsFullscreenDetector when the page is
destroyed

There's a situation that hits a DCHECK() in
MediaCustomControlsFullscreenDetector when the video become
fullscreen but the page navigates away before the timer fires.
This CL solves the issue by stopping the timer when the
ExecutionContext is destroyed.

This CL also moves the common parts of MockWebMediaPlayer into
EmptyWebMediaPlayer. There are still some other
MockWebMediaPlayers which will be adopted in a follow-up.

BUG=698034

Review-Url: https://codereview.chromium.org/2729613007
Cr-Commit-Position: refs/heads/master@{#455740}
(cherry picked from commit fe180eb4effd53064142647a839b89d3910dfff0)

Review-Url: https://codereview.chromium.org/2747633002 .
Cr-Commit-Position: refs/branch-heads/3029@{#136}
Cr-Branched-From:
939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}
Committed:
https://chromium.googlesource.com/chromium/src/+/7bb43d450f514993aa48475c759a...
==========

[Zhiqiang Zhang (Slow), 2017-03-12 18:34:32]

Committed patchset #1 (id:1) manually as
7bb43d450f514993aa48475c759af3a072fa6038 (tree was closed).