Fix the frame freezing issue observed during a config change in the H.264 decoder on Windows

Fix the frame freezing issue observed during a config change in the H.264 decoder on Windows

Merging to M52

We need to drain the decoder of any pending output before tearing down the
instance of the decoder and recreating it during a configuration change.

Draining the decoder is done as part of a Flush operation. However this is
a decoder initiated flush which requires the following
1. Don't process pending input in this case as that is what caused the
   config change.
2. Don't notify the client about the completion of the flush operation.

Added a member variable processing_config_change_ to track this state. We
mimic most of the logic we have to process the pending_flush_ state when
this flag is set.

BUG=616349
Review-Url: https://codereview.chromium.org/2065323002
Cr-Commit-Position: refs/heads/master@{#400023}
(cherry picked from commit ec68dd1bde3f2049975d8aa194525983d4a93688)

Committed: https://chromium.googlesource.com/chromium/src/+/faf72f7be4cb958e249e5a6da6fdf30571487ce1

[ananta, 2016-06-20 20:05:29]

Description was changed from

==========
Fix the frame freezing issue observed during a config change in the H.264
decoder on Windows

Merging to M52

We need to drain the decoder of any pending output before tearing down the
instance of the decoder and recreating it during a configuration change.

Draining the decoder is done as part of a Flush operation. However this is
a decoder initiated flush which requires the following
1. Don't process pending input in this case as that is what caused the
   config change.
2. Don't notify the client about the completion of the flush operation.

Added a member variable processing_config_change_ to track this state. We
mimic most of the logic we have to process the pending_flush_ state when
this flag is set.

BUG=616349

Review-Url: https://codereview.chromium.org/2065323002
Cr-Commit-Position: refs/heads/master@{#400023}
(cherry picked from commit ec68dd1bde3f2049975d8aa194525983d4a93688)
==========

to

==========
Fix the frame freezing issue observed during a config change in the H.264
decoder on Windows

Merging to M52

We need to drain the decoder of any pending output before tearing down the
instance of the decoder and recreating it during a configuration change.

Draining the decoder is done as part of a Flush operation. However this is
a decoder initiated flush which requires the following
1. Don't process pending input in this case as that is what caused the
   config change.
2. Don't notify the client about the completion of the flush operation.

Added a member variable processing_config_change_ to track this state. We
mimic most of the logic we have to process the pending_flush_ state when
this flag is set.

BUG=616349

Review-Url: https://codereview.chromium.org/2065323002
Cr-Commit-Position: refs/heads/master@{#400023}
(cherry picked from commit ec68dd1bde3f2049975d8aa194525983d4a93688)

Committed:
https://chromium.googlesource.com/chromium/src/+/faf72f7be4cb958e249e5a6da6fd...
==========

[ananta, 2016-06-20 20:05:30]

Committed patchset #1 (id:1) manually as
faf72f7be4cb958e249e5a6da6fdf30571487ce1.