Fix CPM casting issue; refactor renderer crash events

Fix issue 152275 by removing the cast.  Combine
the now-identical RendererCrash and RendererFreeze events, and rename them for readability/consistency.

BUG=152275, 130212


Review URL: https://chromiumcodereview.appspot.com/10987040

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@159844 0039d316-1c4b-4281-b951-d872f2087c98
13 files changed