Flood-fill the canvas used for layout tests

Otherwise, layout tests that don't damage the entire view access
uninitialized memory.

BUG=332271
R=reed@google.com,thestig@chromium.org

Review URL: https://codereview.chromium.org/128443002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243694 0039d316-1c4b-4281-b951-d872f2087c98
Remove dependencies on base from SampleApp
- Change to use mojo::utility::RunLoop
- Move timer from gles2_client_impl to gles2_impl with added api.

BUG=None
TEST=None
R=darin

Review URL: https://codereview.chromium.org/128813002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243695 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243695