Add fail check for GetKeyboardState() in Windows KeyMap

ui/events/keycodes/platform_key_map_win.cc

 // Copyright (c) 2016 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 "ui/events/keycodes/platform_key_map_win.h"
 
 #include <utility>
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 145 matching lines @@
 
   HKL current_layout = ::GetKeyboardLayout(0);
   platform_key_map->UpdateLayout(current_layout);
   return platform_key_map->DomCodeAndFlagsToDomKey(code, flags);
 }
 
 void PlatformKeyMap::UpdateLayout(HKL layout) {
   if (layout == keyboard_layout_)
     return;
 
+  BYTE keyboard_state_to_restore[256];
+  if (!::GetKeyboardState(keyboard_state_to_restore))
+    return;
+
   // TODO(chongz): Optimize layout switching (see crbug.com/587147).
   keyboard_layout_ = layout;
   code_to_key_.clear();
   // Map size for some sample keyboard layouts:
   // US: 428, French: 554, Persian: 434, Vietnamese: 1388
   code_to_key_.reserve(500);
 
-  BYTE keyboard_state_to_restore[256];
-  ::GetKeyboardState(keyboard_state_to_restore);
-
   for (int eindex = 0; eindex <= kModifierFlagsCombinations; ++eindex) {
     BYTE keyboard_state[256];
     memset(keyboard_state, 0, sizeof(keyboard_state));
     int flags = GetModifierFlags(eindex);
     SetModifierState(keyboard_state, flags);
     for (const auto& dom_code_entry : supported_dom_code_list) {
       wchar_t translated_chars[5];
       int key_code = ::MapVirtualKeyEx(dom_code_entry.scan_code,
                                        MAPVK_VSC_TO_VK, keyboard_layout_);
       int rv = ::ToUnicodeEx(key_code, 0, keyboard_state, translated_chars,
@@ skipping 23 matching lines @@
         }
       } else {
         // TODO(chongz): Handle rv <= -2 and rv >= 2.
       }
     }
   }
   ::SetKeyboardState(keyboard_state_to_restore);
 }
 
 }  // namespace ui