Add chrome.inputMethodPrivate.onImeMenuActivationChanged API.

ui/base/ime/chromeos/input_method_manager.h

Index: ui/base/ime/chromeos/input_method_manager.h
diff --git a/ui/base/ime/chromeos/input_method_manager.h b/ui/base/ime/chromeos/input_method_manager.h
index 2f7012331af4c78d1263a3080b4008c6d8749efc..fe90bb3211be623e60f7c4169b452c3184f8583f 100644
--- a/ui/base/ime/chromeos/input_method_manager.h
+++ b/ui/base/ime/chromeos/input_method_manager.h
@@ -69,6 +69,16 @@ class UI_BASE_IME_EXPORT InputMethodManager {
     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.
@@ -203,9 +213,11 @@ class UI_BASE_IME_EXPORT InputMethodManager {
   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
@@ -245,6 +257,9 @@ class UI_BASE_IME_EXPORT InputMethodManager {
 
   // 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