Suspend shared timers while blockingly closing databases

BUG=388771
R=michaeln@chromium.org

Review URL: https://codereview.chromium.org/409863002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284785 0039d316-1c4b-4281-b951-d872f2087c98
void RenderThreadImpl::RegisterExtension(v8::Extension* extension) {
  WebScriptController::registerExtension(extension);
}

void RenderThreadImpl::RegisterExtension(v8::Extension* extension) {
  WebScriptController::registerExtension(extension);
}
