Add hw_video_decode_mac flag for Flash 15.0.0.223.

Add hw_video_decode_mac flag for Flash 15.0.0.223.

After 15.0.0.223 Flash version Adobe will use enable_hw_video_decode
like on all other platforms. For a short period of time use both flags.

BUG=335836
TEST=None.

Committed: https://crrev.com/722d18237a29c2f75fbfcccbe8c7afb35179628b
Cr-Commit-Position: refs/heads/master@{#303600}

[ilja, 2014-11-04 00:35:47]

ihf@chromium.org changed reviewers:
+ ccameron@chromium.org, sandersd@chromium.org

[sandersd (OOO until July 31), 2014-11-04 18:21:09]

lgtm

I'm not actually sure what the initial value for this flag should be yet, so it
may be unnecessary.

[ilja, 2014-11-04 19:47:18]

All platforms use enable_hw_video_decode. This was changed for mac to
enable_hw_video_decode_mac, but reverted after 15.0.0.223. This means if we want
to test hardware decode in 41, then until the next Flash binary arrives (in a
few weeks) we will need the enable_hw_video_decode_mac flag (in fact this change
uses both).

[ilja, 2014-11-04 19:48:59]

ihf@chromium.org changed reviewers:
+ sievers@chromium.org

[ilja, 2014-11-04 19:49:58]

sievers: could you please do an OWNERS review?

[no sievers, 2014-11-04 21:54:23]

On 2014/11/04 19:49:58, ilja wrote:
> sievers: could you please do an OWNERS review?

lgtm

[ilja, 2014-11-04 23:35:15]

sandersd: I plan to land this after the branching point, as you mentioned before
that the target for decode is M-41.

[ilja, 2014-11-11 06:49:00]

The CQ bit was checked by ihf@chromium.org

[commit-bot: I haz the power, 2014-11-11 06:49:25]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/699083002/1

[commit-bot: I haz the power, 2014-11-11 07:42:50]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-11-11 07:43:29]

Patchset 1 (id:??) landed as
https://crrev.com/722d18237a29c2f75fbfcccbe8c7afb35179628b
Cr-Commit-Position: refs/heads/master@{#303600}