Add chrome.inputMethodPrivate.onImeMenuActivationChanged API.

ui/base/ime/chromeos/input_method_manager.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_BASE_IME_CHROMEOS_INPUT_METHOD_MANAGER_H_
 #define UI_BASE_IME_CHROMEOS_INPUT_METHOD_MANAGER_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 51 matching lines @@
   // keyboard is used, since it controls its own candidate window.
   class CandidateWindowObserver {
    public:
     virtual ~CandidateWindowObserver() {}
     // Called when the candidate window is opened.
     virtual void CandidateWindowOpened(InputMethodManager* manager) = 0;
     // Called when the candidate window is closed.
     virtual void CandidateWindowClosed(InputMethodManager* manager) = 0;
   };
 
+  // ImeMenuObserver is notified of events related to the IME menu on the shelf
+  // bar.
+  class ImeMenuObserver {
+   public:
+    virtual ~ImeMenuObserver() {}
+    // Called when the IME menu is activated/deactivated. Notices to activate

[michaelpg, 2016/01/08 03:08:54]

"Notices to activate"? Can you make this clearer?

If you just mean that |activation| specifies whether activation was set to true
or false, the comment is redundant. Or, are you trying to describe what the
behavior of the virtual function should be?

[Azure Wei, 2016/01/08 03:26:05]

Yeah, I simply mean that |activation| specifies whether activate or deactivate
the IME menu. I've deleted this redundant comment. 

+    // the IME menu if |activation| is true.
+    virtual void ImeMenuActivationChanged(bool activation) = 0;
+  };
+
   class State : public base::RefCounted<InputMethodManager::State> {
    public:
     // Returns a copy of state.
     virtual scoped_refptr<State> Clone() const = 0;
 
     // Adds an input method extension. This function does not takes ownership of
     // |instance|.
     virtual void AddInputMethodExtension(
         const std::string& extension_id,
         const InputMethodDescriptors& descriptors,
@@ skipping 114 matching lines @@
   static UI_BASE_IME_EXPORT void Shutdown();
 
   // Get the current UI session state (e.g. login screen, lock screen, etc.).
   virtual UISessionState GetUISessionState() = 0;
 
   // Adds an observer to receive notifications of input method related
   // changes as desribed in the Observer class above.
   virtual void AddObserver(Observer* observer) = 0;
   virtual void AddCandidateWindowObserver(
       CandidateWindowObserver* observer) = 0;
+  virtual void AddImeMenuObserver(ImeMenuObserver* observer) = 0;
   virtual void RemoveObserver(Observer* observer) = 0;
   virtual void RemoveCandidateWindowObserver(
       CandidateWindowObserver* observer) = 0;
+  virtual void RemoveImeMenuObserver(ImeMenuObserver* observer) = 0;
 
   // Returns all input methods that are supported, including ones not active.
   // This function never returns NULL. Note that input method extensions are NOT
   // included in the result.
   virtual scoped_ptr<InputMethodDescriptors>
       GetSupportedInputMethods() const = 0;
 
   // Activates the input method property specified by the |key|.
   virtual void ActivateInputMethodMenuItem(const std::string& key) = 0;
 
@@ skipping 19 matching lines @@
       std::vector<std::string>* input_method_ids) = 0;
 
   // Returns new empty state for the |profile|.
   virtual scoped_refptr<State> CreateNewState(Profile* profile) = 0;
 
   // Returns active state.
   virtual scoped_refptr<InputMethodManager::State> GetActiveIMEState() = 0;
 
   // Replaces active state.
   virtual void SetState(scoped_refptr<State> state) = 0;
+
+  // Activates or deactivates the IME Menu.
+  virtual void ImeMenuActivationChanged(bool activation) = 0;
 };
 
 }  // namespace input_method
 }  // namespace chromeos
 
 #endif  // UI_BASE_IME_CHROMEOS_INPUT_METHOD_MANAGER_H_