android: Fix restoring compositor render surface

https://codereview.chromium.org/157053005 made it possible to switch the
compositor's render surface format, but introduced a bug when the render
surface is destroyed and recreated using the same format as before. The
result is that when Chrome loses focus, it is unable to restore the
render surface when the app is focused again.

The fix is to reset the current render surface format when the surface
gets destroyed.

BUG=321610,342411

Review URL: https://codereview.chromium.org/159003005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250382 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250382
Add missing OS_WIN check in ChromeShellDelegate.

Review URL: https://codereview.chromium.org/150943003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@250383 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 250383