Switch from thread-local to thread-safe EventNames

This CL is the last one to switch from using thread-local storage for event
names to using thread-safe strings. This CL is almost entirely generated by a
regular expression find-and-replace.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/26559003

git-svn-id: svn://svn.chromium.org/blink/trunk@159158 bbb929c8-8fbe-4397-9dbb-9b2b20218538