Remove code that checks if MessagePumpForGpu was signaled.

base/message_loop/message_loop.h

Index: base/message_loop/message_loop.h
diff --git a/base/message_loop/message_loop.h b/base/message_loop/message_loop.h
index 5b1728e439396df819bda5a29e2c1773c0a4a378..4f3250c3b7f1b164d984dc0e4dcee28866092015 100644
--- a/base/message_loop/message_loop.h
+++ b/base/message_loop/message_loop.h
@@ -316,15 +316,6 @@ class BASE_EXPORT MessageLoop : public MessagePump::Delegate {
   // Runs the specified PendingTask.
   void RunTask(const PendingTask& pending_task);
 
-#if defined(OS_WIN)
-  // TODO (stanisc): crbug.com/596190: Remove this after the signaling issue
-  // has been investigated.
-  // This should be used for diagnostic only. If message pump wake-up mechanism
-  // is based on auto-reset event this call would reset the event to unset
-  // state.
-  bool MessagePumpWasSignaled();
-#endif
-
   //----------------------------------------------------------------------------
  protected:
   std::unique_ptr<MessagePump> pump_;