Merge M47: "Add event to media log if origin changes during playback"

Merge M47: "Add event to media log if origin changes during playback"

As this issue has happened at least twice, add a entry in
chrome://media-internals so that an origin change that is not
allowed is noted in the logs to simplify debugging the issue.

BUG=532569, 544911
TEST=entry added when using test case from 544911
TBR=jrummell

Review URL: https://codereview.chromium.org/1418533005

Cr-Commit-Position: refs/heads/master@{#355484}
(cherry picked from commit 66282c1dd37989c997962c2bd1d232cef0354418)

Committed: https://chromium.googlesource.com/chromium/src/+/7b8c0137a5badeb7dba92475b5c5f0dd18692270

[DaleCurtis, 2015-10-26 18:03:57]

Committed patchset #1 (id:1) manually as
7b8c0137a5badeb7dba92475b5c5f0dd18692270.