GitLab

After the context is created, the remaining calls should be done on
the compositor thread. This CL adds a MaybeInitializeGL() method, which
we run on each call to makeContextCurrent().

Added asserts to RendererGLContext to check that it's always used on
the same thread.

Review URL: http://codereview.chromium.org/7713015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@98392 0039d316-1c4b-4281-b951-d872f2087c98