[Cast] Repurpose CastInitializationStatus for variable frame size support.

[Cast] Repurpose CastInitializationStatus for variable frame size support.

1. Renamed the CastInitializationStatus enum to OperationalStatus.
2. Renamed CastInitializationCallback to StatusChangeCallback.
3. Documented use of enum and callback.
4. Callbacks may now be run repeatedly to indicate when codec reinit
   occurs (e.g., for a frame size change), and whether runtime errors
   occur after initialization.

BUG=451277
Committed: https://crrev.com/6377eb4a7055d3135e286e71b563ccd100ed4669
Cr-Commit-Position: refs/heads/master@{#315187}

[miu, 2015-02-05 22:39:38]

miu@chromium.org changed reviewers:
+ hclam@chromium.org

[miu, 2015-02-05 22:39:38]

hclam: PTAL.

[Alpha Left Google, 2015-02-07 01:18:58]

https://codereview.chromium.org/901833004/diff/20001/chrome/renderer/media/ca...
File chrome/renderer/media/cast_session_delegate.cc (right):

https://codereview.chromium.org/901833004/diff/20001/chrome/renderer/media/ca...
chrome/renderer/media/cast_session_delegate.cc:240: break;
Can we log this or there's already a log for frame size change in the encoder?

[miu, 2015-02-07 01:37:02]

https://codereview.chromium.org/901833004/diff/20001/chrome/renderer/media/ca...
File chrome/renderer/media/cast_session_delegate.cc (right):

https://codereview.chromium.org/901833004/diff/20001/chrome/renderer/media/ca...
chrome/renderer/media/cast_session_delegate.cc:240: break;
On 2015/02/07 01:18:57, Alpha wrote:
> Can we log this or there's already a log for frame size change in the encoder?

Yes, there's logging there:
https://code.google.com/p/chromium/codesearch#chromium/src/media/cast/sender/...

(and in a soon-upcoming change, I'll have similar logging for the platform
encoders)

[Alpha Left Google, 2015-02-07 02:36:18]

Okay. LGTM.

[miu, 2015-02-07 05:20:33]

The CQ bit was checked by miu@chromium.org

[commit-bot: I haz the power, 2015-02-07 05:21:29]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/901833004/20001

[commit-bot: I haz the power, 2015-02-07 05:25:39]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2015-02-07 05:27:00]

Patchset 2 (id:??) landed as
https://crrev.com/6377eb4a7055d3135e286e71b563ccd100ed4669
Cr-Commit-Position: refs/heads/master@{#315187}