Implement per-test timeout for UI tests.

chrome/test/automation/automation_proxy.h

Index: chrome/test/automation/automation_proxy.h
diff --git a/chrome/test/automation/automation_proxy.h b/chrome/test/automation/automation_proxy.h
index dac3bc3872229d4a98c308efc1714bf8acf638a8..bcb91b30ef8b43fbda2af1d1a5ffe8b44fbe4548 100644
--- a/chrome/test/automation/automation_proxy.h
+++ b/chrome/test/automation/automation_proxy.h
@@ -80,6 +80,8 @@ class AutomationProxy : public IPC::Channel::Listener,
   // Returns true if the load is successful
   bool WaitForInitialLoads();
 
+  bool QuitAfterTimeout(int timeout_ms);
+
   // Waits for the initial destinations tab to report that it has finished
   // querying.  |load_time| is filled in with how long it took, in milliseconds.
   // NOTE: this only fires once for a run of the application.