Supply empty frames until codec is done with top-off.

Supply empty frames until codec is done with top-off.

Previously the VideoEncoderVpx would pass up to two empty/unchanged
frames to the codec when in lossy-VP9 mode, to allow some quality
top-off even if the desktop is otherwise idle. VideoEncoderVpx now calls
the codec until it reports that no changes were encoded.

This CL also uses a DesktopSize to hold the active-map dimensions.

BUG=134202
Committed: https://crrev.com/9242f6c195c4b6ed37c1e565362f8324f9edc879
Cr-Commit-Position: refs/heads/master@{#338371}

[Wez, 2015-07-02 16:57:27]

wez@chromium.org changed reviewers:
+ sergeyu@chromium.org

[Wez, 2015-07-02 16:57:28]

PTAL

[Sergey Ulanov, 2015-07-06 17:58:29]

lgtm

https://codereview.chromium.org/1213323003/diff/20001/remoting/codec/video_en...
File remoting/codec/video_encoder_vpx.h (right):

https://codereview.chromium.org/1213323003/diff/20001/remoting/codec/video_en...
remoting/codec/video_encoder_vpx.h:79: bool encode_unchanged_frame_;
= false; and remove initializer in the constructor

https://codereview.chromium.org/1213323003/diff/20001/remoting/codec/video_en...
remoting/codec/video_encoder_vpx.h:79: bool encode_unchanged_frame_;
maybe call it encode_next_unchanged_frame_ to make it clear that it affects only
next frame?

[Wez, 2015-07-08 23:48:17]

The CQ bit was checked by wez@chromium.org

[commit-bot: I haz the power, 2015-07-08 23:48:30]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1213323003/20001

[commit-bot: I haz the power, 2015-07-09 00:24:25]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-09 00:24:26]

Try jobs failed on following builders:
  linux_chromium_rel_ng on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/linux_chromium_...)

(exceeded global retry quota)

[Wez, 2015-07-10 21:04:00]

The CQ bit was checked by wez@chromium.org

[Wez, 2015-07-10 21:04:00]

The patchset sent to the CQ was uploaded after l-g-t-m from sergeyu@chromium.org
Link to the patchset: https://codereview.chromium.org/1213323003/#ps40001
(title: "Loosen top-off frame count tests")

[commit-bot: I haz the power, 2015-07-10 21:07:39]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1213323003/40001

[commit-bot: I haz the power, 2015-07-10 21:43:39]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2015-07-10 21:46:04]

Patchset 3 (id:??) landed as
https://crrev.com/9242f6c195c4b6ed37c1e565362f8324f9edc879
Cr-Commit-Position: refs/heads/master@{#338371}