Revert 216278 "Clean up compositor initialization/destruction."

Revert 216278 "Clean up compositor initialization/destruction."

interactive_ui_test failures in TabDragging tests:
http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%282%29/builds/17046

> Clean up compositor initialization/destruction.
> 
> Moved from https://codereview.chromium.org/21052007/
> 
> Currently the ContextFactory is outliving the compositor thread in
> tests, which is bad since the contexts in there can be bound to the
> compositor thread. Then we end up reusing those contexts and bad
> things happen.
> 
> This enforces ordering for initializing and destroying the
> compositor as follows:
> 
> Initialize ContextFactory
> ..Compositor::Initialize
> ....Create Compositor instances
> ....Delete Compositor instances
> ..Compositor::Terminate
> 
> The Compositor::Terminate call also destroys the ContextFactory.
> 
> The ContextFactory can be initialized in one of two ways:
> 1. ImageTransportFactory::Initialize will set up the
> ContextFactory. This is used by things that invoke all of
> content/browser/.
> 2. Compositor::InitializeContextFactoryForTests() must be
> explicitly called by any unit tests that create a compositor.
> 
> Since some tests want a real GL context and some don't, this
> does away with the misnomer of initializing the Compositor once
> for the entire test suite, and then re-initializing somewhere
> in the middle of the test suite. Instead, each test must
> Initialize/Terminate the compositor with the ContextFactory
> type of its choice.
> 
> Incidently, this test enables 20 tests on aura or win_aura that
> were previously being skipped.
> 
> TBR=piman@chromium.org
> BUG=258625
> 
> Review URL: https://codereview.chromium.org/22293003

TBR=danakj@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=216294

[not at google - send to devlin, 2013-08-07 22:55:47]

Committed patchset #1 manually as r216294.