cc: Make OutputSurface entirely live on one thread in tests.

OutputSurface is single-threaded but it ends up being created on the
main thread and used on compositor thread in cc unit tests and layout
tests, where it is directly attached to the renderer compositor.

Rework these tests so OutputSurface is only on a single thread to
reduce complexity of the class (will allow removal of BindToClient
entirely).

R=enne@chromium.org
BUG=606056
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_precise_blink_rel

Review-Url: https://codereview.chromium.org/2445553002
Cr-Commit-Position: refs/heads/master@{#427495}
12 files changed