Update from https://crrev.com/312600

base/message_loop/message_pump_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/message_loop/message_pump_win.h"
 
 #include <math.h>
 
 #include "base/debug/trace_event.h"
 #include "base/message_loop/message_loop.h"
@@ skipping 334 matching lines @@
           "440919 MessagePumpForUI::ProcessNextWindowsMessage2"));
 
   MSG msg;
   if (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE) != FALSE)
     return ProcessMessageHelper(msg);
 
   return sent_messages_in_queue;
 }
 
 bool MessagePumpForUI::ProcessMessageHelper(const MSG& msg) {
+  // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
+  tracked_objects::ScopedTracker tracking_profile1(
+      FROM_HERE_WITH_EXPLICIT_FUNCTION(
+          "440919 MessagePumpForUI::ProcessMessageHelper1"));
+
   TRACE_EVENT1("base", "MessagePumpForUI::ProcessMessageHelper",
                "message", msg.message);
   if (WM_QUIT == msg.message) {
     // Repost the QUIT message so that it will be retrieved by the primary
     // GetMessage() loop.
     state_->should_quit = true;
     PostQuitMessage(static_cast<int>(msg.wParam));
     return false;
   }
 
   // While running our main message pump, we discard kMsgHaveWork messages.
   if (msg.message == kMsgHaveWork && msg.hwnd == message_hwnd_)
     return ProcessPumpReplacementMessage();
 
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
   tracked_objects::ScopedTracker tracking_profile2(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "440919 MessagePumpForUI::ProcessMessageHelper2"));
 
   if (CallMsgFilter(const_cast<MSG*>(&msg), kMessageFilterCode))
     return true;
 
   // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
   tracked_objects::ScopedTracker tracking_profile3(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
           "440919 MessagePumpForUI::ProcessMessageHelper3"));
 
   uint32_t action = MessagePumpDispatcher::POST_DISPATCH_PERFORM_DEFAULT;
-  if (state_->dispatcher)
+  if (state_->dispatcher) {
+    // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
+    tracked_objects::ScopedTracker tracking_profile4(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(
+            "440919 MessagePumpForUI::ProcessMessageHelper4"));
+
     action = state_->dispatcher->Dispatch(msg);
+  }
   if (action & MessagePumpDispatcher::POST_DISPATCH_QUIT_LOOP)
     state_->should_quit = true;
   if (action & MessagePumpDispatcher::POST_DISPATCH_PERFORM_DEFAULT) {
+    // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
+    tracked_objects::ScopedTracker tracking_profile5(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(
+            "440919 MessagePumpForUI::ProcessMessageHelper5"));
+
     TranslateMessage(&msg);
+
+    // TODO(vadimt): Remove ScopedTracker below once crbug.com/440919 is fixed.
+    tracked_objects::ScopedTracker tracking_profile6(
+        FROM_HERE_WITH_EXPLICIT_FUNCTION(
+            "440919 MessagePumpForUI::ProcessMessageHelper6"));
+
     DispatchMessage(&msg);
   }
 
   return true;
 }
 
 bool MessagePumpForUI::ProcessPumpReplacementMessage() {
   // When we encounter a kMsgHaveWork message, this method is called to peek
   // and process a replacement message, such as a WM_PAINT or WM_TIMER.  The
   // goal is to make the kMsgHaveWork as non-intrusive as possible, even though
@@ skipping 254 matching lines @@
 
 // static
 MessagePumpForIO::IOHandler* MessagePumpForIO::KeyToHandler(
     ULONG_PTR key,
     bool* has_valid_io_context) {
   *has_valid_io_context = ((key & 1) == 0);
   return reinterpret_cast<IOHandler*>(key & ~static_cast<ULONG_PTR>(1));
 }
 
 }  // namespace base