Remove the 2-level input method system & InputMethodBridge.

ui/views/controls/combobox/combobox.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.
 
 #ifndef UI_VIEWS_CONTROLS_COMBOBOX_COMBOBOX_H_
 #define UI_VIEWS_CONTROLS_COMBOBOX_COMBOBOX_H_
 
 #include <string>
 
 #include "base/memory/weak_ptr.h"
@@ skipping 74 matching lines @@
 
   // Set the accessible name of the combobox.
   void SetAccessibleName(const base::string16& name);
 
   // Visually marks the combobox as having an invalid value selected.
   // When invalid, it paints with white text on a red background.
   // Callers are responsible for restoring validity with selection changes.
   void SetInvalid(bool invalid);
   bool invalid() const { return invalid_; }
 
+  ui::TextInputClient* GetTextInputClient();

[yukawa, 2015/06/16 02:45:03]

I prefer to use more descriptive name such as
   PrefixSelector* GetPrefixSelector();
What do you think?

Also, can this be private method?

[Shu Chen, 2015/06/16 05:15:26]

Done.

+
   // Overridden from View:
   gfx::Size GetPreferredSize() const override;
   const char* GetClassName() const override;
   bool SkipDefaultKeyEventProcessing(const ui::KeyEvent& e) override;
   bool OnKeyPressed(const ui::KeyEvent& e) override;
   bool OnKeyReleased(const ui::KeyEvent& e) override;
   void OnPaint(gfx::Canvas* canvas) override;
   void OnFocus() override;
   void OnBlur() override;
   void GetAccessibleState(ui::AXViewState* state) override;
-  ui::TextInputClient* GetTextInputClient() override;
   void Layout() override;
 
   // Overridden from MenuDelegate:
   bool IsItemChecked(int id) const override;
   bool IsCommandEnabled(int id) const override;
   void ExecuteCommand(int id) override;
   bool GetAccelerator(int id, ui::Accelerator* accelerator) const override;
 
   // Overridden from PrefixDelegate:
   int GetRowCount() override;
@@ skipping 107 matching lines @@
 
   // Used for making calbacks.
   base::WeakPtrFactory<Combobox> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Combobox);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_COMBOBOX_COMBOBOX_H_