GPU process: Add a SEH handler to the compositor window proc.
GPU process: Add a SEH handler to the compositor window proc.

BUG=63702
TEST=none
Review URL: http://codereview.chromium.org/6705017

git-svn-id: http://src.chromium.org/svn/trunk/src@79326 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 38554ed52319773b660f61010fdb08fa893010c6
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser