gpu: Refactor GpuMemoryBuffer framework for multi-process support.
    
This removes the ImageFactory interface and adjusts the buffer
allocation system for future multi-process support.

Also includes proper plumbing of internalformat to GLImage implementation
and makes sure the compositor is using the correct format.
    
TEST=gpu_unittests --gtest_filter=MockGpuMemoryBufferTest.Lifecycle
BUG=261649

Review URL: https://chromiumcodereview.appspot.com/20017005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@218034 0039d316-1c4b-4281-b951-d872f2087c98
45 files changed