Move more framebuffer state out of ContextState and into FramebufferState.
This will us (in future CLs) to not pass in ContextState into FramebufferManager,
but just the FramebufferState.

Review URL: https://codereview.chromium.org/25277005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226374 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226374