cc: Fix incomplete changes to add ETC1 support

ETC1 resources was recently added (https://codereview.chromium.org/27973002),
but the change did not cover the LayerTreeHostImpl path, which cause crashes
when one tries to use ETC1 UIResourceBitmap.  This update adds in the missing
changes.

BUG=314749

Review URL: https://codereview.chromium.org/41903003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233874 0039d316-1c4b-4281-b951-d872f2087c98
9 files changed