Enables using the magnification API for screen capturing on Windows under a Finch experiment.

Enables using the magnification API for screen capturing on Windows under a Finch experiment.
NOTRY=true
NOTREECHECKS=true
BUG=https://code.google.com/p/webrtc/issues/detail?id=2789

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=269444

[jiayl, 2014-05-05 17:18:09]

asvitkine: please review the use of the new experiment
sergeyu: please review the rest

[Sergey Ulanov, 2014-05-05 20:10:06]

https://codereview.chromium.org/268123003/diff/30001/content/browser/media/ca...
File content/browser/media/capture/desktop_capture_device.cc (right):

https://codereview.chromium.org/268123003/diff/30001/content/browser/media/ca...
content/browser/media/capture/desktop_capture_device.cc:157:
DesktopCaptureDevice::Core::Core(scoped_ptr<base::Thread> thread,
Same as with DesktopCaptureDevice, better to avoid overriding constructor, and
it's easy to avoid it here. E.g. it's error prone when adding initializers for
new class members.

https://codereview.chromium.org/268123003/diff/30001/content/browser/media/ca...
content/browser/media/capture/desktop_capture_device.cc:421:
scoped_refptr<base::SequencedTaskRunner> task_runner =
There is no point creating task runner if it's not used. Move this inside the if
block where the constructor is called?

https://codereview.chromium.org/268123003/diff/30001/content/browser/media/ca...
content/browser/media/capture/desktop_capture_device.cc:438: bool
magnification_allowed = base::FieldTrialList::FindFullName(
indent 2 spaces.

https://codereview.chromium.org/268123003/diff/30001/content/browser/media/ca...
content/browser/media/capture/desktop_capture_device.cc:482: if
(task_runner.get()) {
if (!ui_thread)

https://codereview.chromium.org/268123003/diff/30001/content/browser/media/ca...
File content/browser/media/capture/desktop_capture_device.h (right):

https://codereview.chromium.org/268123003/diff/30001/content/browser/media/ca...
content/browser/media/capture/desktop_capture_device.h:43:
DesktopCaptureDevice(scoped_ptr<base::Thread> thread,
It's better to avoid overriding constructor. I suggest making constructor
private and always passing both |task_runner| and |thread|. The constructor is
called from Create() and from unittests. So you'll need to befriend this class
with DesktopCaptureDeviceTest.

[jiayl, 2014-05-05 21:00:27]

PTAL

[jiayl, 2014-05-07 16:28:13]

Ping reviewers.

[Alexei Svitkine (slow), 2014-05-07 16:57:30]

lgtm for use of field trial

[Sergey Ulanov, 2014-05-07 19:53:09]

lgtm

[jiayl, 2014-05-08 16:20:18]

The CQ bit was checked by jiayl@chromium.org

[commit-bot: I haz the power, 2014-05-08 16:22:57]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jiayl@chromium.org/268123003/50001

[commit-bot: I haz the power, 2014-05-08 20:43:07]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  android_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)

[commit-bot: I haz the power, 2014-05-08 22:07:00]

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

[commit-bot: I haz the power, 2014-05-08 22:07:01]

Try jobs failed on following builders:
  android_dbg_triggered_tests on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/android_dbg_triggered...)

[jiayl, 2014-05-08 22:08:30]

The CQ bit was checked by jiayl@chromium.org

[commit-bot: I haz the power, 2014-05-08 22:16:18]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jiayl@chromium.org/268123003/50001

[commit-bot: I haz the power, 2014-05-08 23:47:40]

FYI, CQ is re-trying this CL (attempt #1).
Please consider checking whether the failures are real,
and report flakes to chrome-troopers@google.com.
The failing builders are:
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)

[commit-bot: I haz the power, 2014-05-09 05:48:09]

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

[commit-bot: I haz the power, 2014-05-09 05:48:10]

Try jobs failed on following builders:
  win_chromium_rel on tryserver.chromium
(http://build.chromium.org/p/tryserver.chromium/builders/win_chromium_rel/buil...)

[jiayl, 2014-05-09 15:39:47]

The CQ bit was checked by jiayl@chromium.org

[commit-bot: I haz the power, 2014-05-09 15:40:42]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jiayl@chromium.org/268123003/50001

[jiayl, 2014-05-09 22:27:18]

The CQ bit was unchecked by jiayl@chromium.org

[jiayl, 2014-05-09 22:27:33]

The CQ bit was checked by jiayl@chromium.org

[commit-bot: I haz the power, 2014-05-09 22:29:44]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/jiayl@chromium.org/268123003/50001

[commit-bot: I haz the power, 2014-05-09 22:45:24]

Change committed as 269444