Fix a regression where we send too many IME_CANCEL_COMPOSITION events back to the browser.
Fix a regression where we send too many IME_CANCEL_COMPOSITION
events back to the browser.

This isn't a problem on OSX because we clear the compositon before
sending WebCompositionCommandDiscard (hbono even asked about this
during the OSX review).

BUG=45003

Review URL: http://codereview.chromium.org/2247003

git-svn-id: http://src.chromium.org/svn/trunk/src@48251 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 72bccb64e04d2a6fd765dcc58295485f66da8e6b
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