Fix a bunch of minor Coverity issues.

- pass more things by const reference
- check return codes (minor severity)

Review URL: http://codereview.chromium.org/149643

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@20731 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/common/worker_thread_ticker.cc b/chrome/common/worker_thread_ticker.cc
index 4351cae5..6d0619f 100644
--- a/chrome/common/worker_thread_ticker.cc
+++ b/chrome/common/worker_thread_ticker.cc
@@ -76,8 +76,9 @@
   AutoLock lock(lock_);
   if (IsRunning())
     return false;
+  if (!timer_thread_.Start())
+    return false;
   is_running_ = true;
-  timer_thread_.Start();
   ScheduleTimerTask();
   return true;
 }