ThreadWatcher - give ShutdownWatchDogThread::Alarm a more unique function body.

chrome/browser/metrics/thread_watcher.cc

Index: chrome/browser/metrics/thread_watcher.cc
===================================================================
--- chrome/browser/metrics/thread_watcher.cc	(revision 192196)
+++ chrome/browser/metrics/thread_watcher.cc	(working copy)
@@ -51,6 +51,10 @@
 #endif
 }
 
+NOINLINE void ShutdownCrash() {
+  NullPointerCrash(__LINE__);
+}
+
 NOINLINE void ThreadUnresponsive_UI() {
   NullPointerCrash(__LINE__);
 }
@@ -873,7 +877,7 @@
   // Alarm is called if the time expires after an Arm() without someone calling
   // Disarm(). We crash the browser if this method is called.
   virtual void Alarm() OVERRIDE {
-    CHECK(false);
+    ShutdownCrash();
   }
 
   DISALLOW_COPY_AND_ASSIGN(ShutdownWatchDogThread);