Combine the WM_CHAR with WM_KEY* for key event flow.

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 <limits>
 #include <math.h>
 
 #include "base/message_loop/message_loop.h"
@@ skipping 382 matching lines @@
   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) {
-    TranslateMessage(&msg);
+  // Don't call TranslateMessage() here but call TranslateMessage() in
+  // InputMethodWin, so that the WM_KEYDOWN/WM_KEYUP & WM_CHAR can be combined
+  // for key event flow. The combination of key events is required for Chrome
+  // IMEs, which can do IME related actions based on the single key event.
+  if (action & MessagePumpDispatcher::POST_DISPATCH_PERFORM_DEFAULT)
     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
   // a continuous stream of such messages are posted.  This method carefully
   // peeks a message while there is no chance for a kMsgHaveWork to be pending,
@@ skipping 255 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