Query the preferred readback config in CopyFromBackingStore

As of now we are using the default format for both android/aura to read the snapshot, but as we have different format readbacks supported we should be able to decide the format before calling copyFromCompsitingSurface
based on some criteria.

BUG= 323150

Review URL: https://codereview.chromium.org/188633002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256812 0039d316-1c4b-4281-b951-d872f2087c98
Request translate language list for all platforms.

Somehow the request for languages excluded android which means that the
first translate request takes much longer since there it is not pre-fetched.

BUG=350932

Review URL: https://codereview.chromium.org/194693005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256813 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256812
(Cleanup) Remove .Times(1) from the VideoCaptureManagerTest unit tests EXPECT_CALLs.

This is a follow-up cleanup cl to remove the .Times(1)
placed at the end of some EXPECT_CALL constructs in the test.
Since this .Times(1) is the by default behaviour, it can be
removed.

BUG=325740

Review URL: https://codereview.chromium.org/197473003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256814 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256814