cc: Avoid issuing COMMANDS_COMPLETED queries unless necessary.

Minor change to the Fence API that allows GLRenderer to not
issue sync queries unless some resource that depend on them
was used to produce a frame.

Also includes some minor renaming cleanup related to usage of
Fences in ResourceProvider code.

BUG=

Review URL: https://codereview.chromium.org/398543004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284318 0039d316-1c4b-4281-b951-d872f2087c98
(cherry picked from commit 2981c2d899f1dde567d3508f63b898981d7d06a2)
Merge pull request #190 from sqliu/cherry-pick

[Temp] Backport r284318 from Chromium.