Don't restart the GPU process when switching to another TTY

content/gpu/gpu_watchdog_thread.h

Index: content/gpu/gpu_watchdog_thread.h
diff --git a/content/gpu/gpu_watchdog_thread.h b/content/gpu/gpu_watchdog_thread.h
index c8e00952b26bf8e6c6fe717b02d054bc12574dc9..68d3cd8cb8d7c9b6574e69fa21f21d418b311b5a 100644
--- a/content/gpu/gpu_watchdog_thread.h
+++ b/content/gpu/gpu_watchdog_thread.h
@@ -91,6 +91,10 @@ class GpuWatchdogThread : public base::Thread,
   base::ThreadTicks GetWatchedThreadTime();
 #endif
 
+#if defined(USE_X11)
+  int GetActiveTTY() const;
+#endif
+
   base::MessageLoop* watched_message_loop_;
   base::TimeDelta timeout_;
   volatile bool armed_;
@@ -127,14 +131,12 @@ class GpuWatchdogThread : public base::Thread,
   base::Time check_time_;
   base::TimeTicks check_timeticks_;
 
-#if defined(OS_CHROMEOS)
-  FILE* tty_file_;
-#endif
-
 #if defined(USE_X11)
   XDisplay* display_;
   gfx::AcceleratedWidget window_;
   XAtom atom_;
+  FILE* tty_file_;
+  int host_tty_;
 #endif
 
   base::WeakPtrFactory<GpuWatchdogThread> weak_factory_;