Disable image transport surface on all windows machines.

We want to try using the direct presentation path everywhere, so blacklist texture sharing on all machines. If this works, we can delete the image transport surface code later.
We've made the image transport surface work even with the sandbox at full strength, so remove the code that reduces the GPU sandbox in this case.

BUG=304369
R=kbr@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=227583

Review URL: https://codereview.chromium.org/26073002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230545 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230545