Fix a crash which occurs due to a CHECK firing in the HWNDMessageHandler::OnKeyEvent code path on W…

ui/events/win/events_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 <windowsx.h>
 
 #include "ui/events/event_constants.h"
 
 #include "base/logging.h"
 #include "base/time/time.h"
@@ skipping 138 matching lines @@
   switch (native_event.message) {
     case WM_KEYDOWN:
     case WM_SYSKEYDOWN:
     case WM_CHAR:
       return ET_KEY_PRESSED;
     // The WM_DEADCHAR message is posted to the window with the keyboard focus
     // when a WM_KEYUP message is translated. This happens for special keyboard
     // sequences.
     case WM_DEADCHAR:
     case WM_KEYUP:
+    // The WM_SYSDEADCHAR message is posted to a window with keyboard focus
+    // when the WM_SYSKEYDOWN message is translated by the TranslateMessage
+    // function. It specifies the character code of the system dead key.
+    case WM_SYSDEADCHAR:
     case WM_SYSKEYUP:
       return ET_KEY_RELEASED;
     case WM_LBUTTONDBLCLK:
     case WM_LBUTTONDOWN:
     case WM_MBUTTONDBLCLK:
     case WM_MBUTTONDOWN:
     case WM_NCLBUTTONDBLCLK:
     case WM_NCLBUTTONDOWN:
     case WM_NCMBUTTONDBLCLK:
     case WM_NCMBUTTONDOWN:
@@ skipping 236 matching lines @@
 }
 
 LPARAM GetLParamFromScanCode(uint16 scan_code) {
   LPARAM l_param = static_cast<LPARAM>(scan_code & 0x00FF) << 16;
   if ((scan_code & 0xE000) == 0xE000)
     l_param |= (1 << 24);
   return l_param;
 }
 
 }  // namespace ui