The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/73fd2eb18f1ed48a1047d737a9db170608ac6f47

commit 73fd2eb18f1ed48a1047d737a9db170608ac6f47
Author: watk <watk@chromium.org>
Date: Fri Mar 18 21:45:57 2016

media: Allow WMPI to send playing started notification while playing

Previously MediaWebContentsObserver DCHECKed that an active player
was never added twice. To avoid complicated logic in WMPI to keep track
of when it's okay to send a playing notification to
MediaWebContentsObserver, now it's allowed to send it more than once.

BUG= 595903 ,  595970 

Review URL: https://codereview.chromium.org/1810213002

Cr-Commit-Position: refs/heads/master@{#382098}

[modify] https://crrev.com/73fd2eb18f1ed48a1047d737a9db170608ac6f47/content/browser/media/media_web_contents_observer.cc
[modify] https://crrev.com/73fd2eb18f1ed48a1047d737a9db170608ac6f47/content/browser/media/media_web_contents_observer.h

Your change meets the bar and is auto-approved for M50 (branch: 2661)

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/217c5e96c255d046fce4a1743b560e7ee5625a82

commit 217c5e96c255d046fce4a1743b560e7ee5625a82
Author: Chris Watkins <watk@chromium.org>
Date: Mon Mar 21 18:08:05 2016

media: Allow WMPI to send playing started notification while playing

Previously MediaWebContentsObserver DCHECKed that an active player
was never added twice. To avoid complicated logic in WMPI to keep track
of when it's okay to send a playing notification to
MediaWebContentsObserver, now it's allowed to send it more than once.

BUG= 595903 ,  595970 

Review URL: https://codereview.chromium.org/1810213002

Cr-Commit-Position: refs/heads/master@{#382098}
(cherry picked from commit 73fd2eb18f1ed48a1047d737a9db170608ac6f47)

Review URL: https://codereview.chromium.org/1821753002 .

Cr-Commit-Position: refs/branch-heads/2661@{#321}
Cr-Branched-From: ef6f6ae5e4c96622286b563658d5cd62a6cf1197-refs/heads/master@{#378081}

[modify] https://crrev.com/217c5e96c255d046fce4a1743b560e7ee5625a82/content/browser/media/media_web_contents_observer.cc
[modify] https://crrev.com/217c5e96c255d046fce4a1743b560e7ee5625a82/content/browser/media/media_web_contents_observer.h

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6b91661ebac34b1096186920caff52cf8b142c55

commit 6b91661ebac34b1096186920caff52cf8b142c55
Author: dalecurtis <dalecurtis@chromium.org>
Date: Tue Mar 22 20:42:36 2016

Release media session and power save blockers for casting.

BUG= 595903 
TEST=none

Review URL: https://codereview.chromium.org/1813373003

Cr-Commit-Position: refs/heads/master@{#382670}

[modify] https://crrev.com/6b91661ebac34b1096186920caff52cf8b142c55/media/blink/webmediaplayer_impl.cc