Move ContextProvider binding to inside GpuVideoAcceleratorFactory

Bind the ContextProvider inside the GpuVideoAcceleratorFactory itself, so the
Factory can decide appropriately what to do in casae of binding failure.

Also: replace references to RendererGpuVideoAcceleratorFactory with references
to its superclass, GpuVideoAcceleratorFactory.

BUG=345424
TEST=local build on desktop Linux
R=avi@chromium.org, fischman@chromium.org

Review URL: https://codereview.chromium.org/171773014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253259 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 253259