Revert 207278 "Make sure that the UI window created by base::Mes..."

trunk/src/base/message_loop/message_pump_win.cc

Index: trunk/src/base/message_loop/message_pump_win.cc
===================================================================
--- trunk/src/base/message_loop/message_pump_win.cc	(revision 207326)
+++ trunk/src/base/message_loop/message_pump_win.cc	(working copy)
@@ -67,10 +67,6 @@
   state_ = previous_state;
 }
 
-void MessagePumpWin::Run(Delegate* delegate) {
-  RunWithDispatcher(delegate, NULL);
-}
-
 void MessagePumpWin::Quit() {
   DCHECK(state_);
   state_->should_quit = true;
@@ -107,33 +103,21 @@
 }
 
 MessagePumpForUI::~MessagePumpForUI() {
-  DCHECK(!atom_);
-  DCHECK(!message_hwnd_);
+  DestroyWindow(message_hwnd_);
+  UnregisterClass(MAKEINTATOM(atom_),
+                  GetModuleFromAddress(&WndProcThunk));
 }
 
 void MessagePumpForUI::ScheduleWork() {
   if (InterlockedExchange(&have_work_, 1))
     return;  // Someone else continued the pumping.
 
-  // If the attempt to acquire the lock fails, the message loop is shutting down
-  // and the message window is about to be destroyed as well.
-  if (!message_hwnd_lock_.Try())
-    return;
+  // Make sure the MessagePump does some work for us.
+  BOOL ret = PostMessage(message_hwnd_, kMsgHaveWork,
+                         reinterpret_cast<WPARAM>(this), 0);
+  if (ret)
+    return;  // There was room in the Window Message queue.
 
-  {
-    base::AutoLock lock(message_hwnd_lock_, base::AutoLock::AlreadyAcquired());
-
-    // Do nothing if the window has been destroyed already.
-    if (!message_hwnd_)
-      return;
-
-    // Make sure the MessagePump does some work for us.
-    if (PostMessage(message_hwnd_, kMsgHaveWork,
-                    reinterpret_cast<WPARAM>(this), 0)) {
-      return;
-    }
-  }
-
   // We have failed to insert a have-work message, so there is a chance that we
   // will starve tasks/timers while sitting in a nested message loop.  Nested
   // loops only look at Windows Message queues, and don't look at *our* task
@@ -188,24 +172,6 @@
                             MESSAGE_LOOP_PROBLEM_MAX);
 }
 
-void MessagePumpForUI::Shutdown() {
-  HWND message_hwnd;
-  {
-    base::AutoLock lock(message_hwnd_lock_);
-
-    // Let ScheduleWork() know that the window has been destoyed.
-    message_hwnd = message_hwnd_;
-    message_hwnd_ = NULL;
-  }
-
-  // Destoy the window and its class. The destructor checks whether
-  // |message_hwnd_| and |atom_| are destroyed, so the variables should be
-  // cleared here.
-  DestroyWindow(message_hwnd);
-  UnregisterClass(MAKEINTATOM(atom_), GetModuleFromAddress(&WndProcThunk));
-  atom_ = 0;
-}
-
 void MessagePumpForUI::PumpOutPendingPaintMessages() {
   // If we are being called outside of the context of Run, then don't try to do
   // any work.
@@ -512,7 +478,7 @@
     return;  // Post worked perfectly.
 
   // See comment in MessagePumpForUI::ScheduleWork() for this error recovery.
-  InterlockedExchange(&have_work_, 0);
+  InterlockedExchange(&have_work_, 0);  // Clarify that we didn't succeed.
   UMA_HISTOGRAM_ENUMERATION("Chrome.MessageLoopProblem", COMPLETION_POST_ERROR,
                             MESSAGE_LOOP_PROBLEM_MAX);
 }
@@ -524,9 +490,6 @@
   delayed_work_time_ = delayed_work_time;
 }
 
-void MessagePumpForIO::Shutdown() {
-}
-
 void MessagePumpForIO::RegisterIOHandler(HANDLE file_handle,
                                          IOHandler* handler) {
   ULONG_PTR key = HandlerToKey(handler, true);