Propagate media play/pause to WebContentsObserver for Chromecast metrics

Propagate media play/pause to WebContentsObserver for Chromecast metrics

Propagate OnMedia{Playing,Paused}Notification to WebContentsObserver and use
this to track Chromecast metrics.

BUG=417000
Committed: https://crrev.com/0c9b968d2dde13e5f01b200f3c9f220a8fdabd93
Cr-Commit-Position: refs/heads/master@{#322282}

[prashantv, 2015-03-25 22:05:58]

prashantv@chromium.org changed reviewers:
+ gunsch@chromium.org, nasko@chromium.org

[nasko, 2015-03-25 22:31:58]

nasko@chromium.org changed reviewers:
+ creis@chromium.org

[nasko, 2015-03-25 22:31:59]

Codewise it looks fine. I think the naming can be improved a bit.

https://codereview.chromium.org/1037593003/diff/1/content/public/browser/web_...
File content/public/browser/web_contents_observer.h (right):

https://codereview.chromium.org/1037593003/diff/1/content/public/browser/web_...
content/public/browser/web_contents_observer.h:347: virtual void
MediaPlayingNotification() {}
The name of this method doesn't quite fit the naming format used by other
observer methods. MediaStartedPlaying or something along those lines seems a bit
better, since "Notification" is somewhat implied from the fact that this is
observer method.

[gunsch, 2015-03-25 22:36:37]

lgtm on Chromecast side, thanks for putting this together!

[prashantv, 2015-03-25 22:44:36]

PTAL

https://codereview.chromium.org/1037593003/diff/1/content/public/browser/web_...
File content/public/browser/web_contents_observer.h (right):

https://codereview.chromium.org/1037593003/diff/1/content/public/browser/web_...
content/public/browser/web_contents_observer.h:347: virtual void
MediaPlayingNotification() {}
On 2015/03/25 22:31:58, nasko wrote:
> The name of this method doesn't quite fit the naming format used by other
> observer methods. MediaStartedPlaying or something along those lines seems a
bit
> better, since "Notification" is somewhat implied from the fact that this is
> observer method.

Done.

[nasko, 2015-03-25 22:52:00]

LGTM

[prashantv, 2015-03-25 23:22:24]

The CQ bit was checked by prashantv@chromium.org

[prashantv, 2015-03-25 23:22:25]

The patchset sent to the CQ was uploaded after l-g-t-m from gunsch@chromium.org
Link to the patchset: https://codereview.chromium.org/1037593003/#ps20001
(title: "renamed observer methods")

[commit-bot: I haz the power, 2015-03-25 23:23:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1037593003/20001

[commit-bot: I haz the power, 2015-03-26 00:59:01]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-03-26 00:59:59]

Patchset 2 (id:??) landed as
https://crrev.com/0c9b968d2dde13e5f01b200f3c9f220a8fdabd93
Cr-Commit-Position: refs/heads/master@{#322282}