Combine the WM_CHAR with WM_KEY* for key event flow.

ui/base/ui_base_switches.h

 // 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.
 
 // Defines all the command-line switches used by ui/base.
 
 #ifndef UI_BASE_UI_BASE_SWITCHES_H_
 #define UI_BASE_UI_BASE_SWITCHES_H_
 
 #include "base/compiler_specific.h"
 #include "ui/base/ui_base_export.h"
 
 namespace switches {
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
 UI_BASE_EXPORT extern const char kDisableMacOverlays[];
 UI_BASE_EXPORT extern const char kDisableRemoteCoreAnimation[];
 UI_BASE_EXPORT extern const char kShowMacOverlayBorders[];
 #endif
 
+#if defined(OS_WIN)
+UI_BASE_EXPORT extern const char kDisableMergeKeyCharEvents[];
+UI_BASE_EXPORT extern const char kEnableMergeKeyCharEvents[];
+#endif
+
 UI_BASE_EXPORT extern const char kDisableDwmComposition[];
 UI_BASE_EXPORT extern const char kDisableIconNtp[];
 UI_BASE_EXPORT extern const char kDisableTouchAdjustment[];
 UI_BASE_EXPORT extern const char kDisableTouchDragDrop[];
 UI_BASE_EXPORT extern const char kDisableTouchFeedback[];
 UI_BASE_EXPORT extern const char kEnableIconNtp[];
 UI_BASE_EXPORT extern const char kEnableLinkDisambiguationPopup[];
 UI_BASE_EXPORT extern const char kEnableTouchDragDrop[];
 UI_BASE_EXPORT extern const char kLang[];
 UI_BASE_EXPORT extern const char kMaterialDesignInkDropAnimationSpeed[];
 UI_BASE_EXPORT extern const char kMaterialDesignInkDropAnimationSpeedFast[];
 UI_BASE_EXPORT extern const char kMaterialDesignInkDropAnimationSpeedSlow[];
 
 #if defined(ENABLE_TOPCHROME_MD)
 UI_BASE_EXPORT extern const char kTopChromeMD[];
 UI_BASE_EXPORT extern const char kTopChromeMDMaterial[];
 UI_BASE_EXPORT extern const char kTopChromeMDMaterialHybrid[];
 UI_BASE_EXPORT extern const char kTopChromeMDNonMaterial[];
 #endif  // defined(ENABLE_TOPCHROME_MD)
 
 UI_BASE_EXPORT extern const char kViewerConnect[];
 
 }  // namespace switches
 
 #endif  // UI_BASE_UI_BASE_SWITCHES_H_