Change some functions in ImeEngineObserver as not ChromeOS-only.

chrome/browser/extensions/api/input_ime/input_ime_api_chromeos.cc

Index: chrome/browser/extensions/api/input_ime/input_ime_api_chromeos.cc
diff --git a/chrome/browser/extensions/api/input_ime/input_ime_api_chromeos.cc b/chrome/browser/extensions/api/input_ime/input_ime_api_chromeos.cc
index db2ad970f82df0cc7c23f70e2ea121c094bc6eb5..7d7e9f68787ea0dc726c8f59eae64e773dc5d5d8 100644
--- a/chrome/browser/extensions/api/input_ime/input_ime_api_chromeos.cc
+++ b/chrome/browser/extensions/api/input_ime/input_ime_api_chromeos.cc
@@ -83,20 +83,6 @@ class ImeObserverChromeOS : public ui::ImeObserver {
   ~ImeObserverChromeOS() override {}
 
   // ui::IMEEngineObserver overrides
-  void OnActivate(const std::string& component_id) override {
-    if (extension_id_.empty() ||
-        !HasListener(input_ime::OnActivate::kEventName))
-      return;
-
-    scoped_ptr<base::ListValue> args(input_ime::OnActivate::Create(
-        component_id,
-        input_ime::ParseScreenType(GetCurrentScreenType())));
-
-    DispatchEventToExtension(extensions::events::INPUT_IME_ON_ACTIVATE,
-                             input_ime::OnActivate::kEventName,
-                             std::move(args));
-  }
-
   void OnInputContextUpdate(
       const IMEEngineHandlerInterface::InputContext& context) override {
     if (extension_id_.empty() ||
@@ -116,10 +102,6 @@ class ImeObserverChromeOS : public ui::ImeObserver {
         input_ime::OnInputContextUpdate::kEventName, std::move(args));
   }
 
-  bool IsInterestedInKeyEvent() const override {
-    return ShouldForwardKeyEvent();
-  }
-
   void OnCandidateClicked(
       const std::string& component_id,
       int candidate_id,
@@ -167,28 +149,6 @@ class ImeObserverChromeOS : public ui::ImeObserver {
         input_ime::OnMenuItemActivated::kEventName, std::move(args));
   }
 
-  void OnSurroundingTextChanged(const std::string& component_id,
-                                const std::string& text,
-                                int cursor_pos,
-                                int anchor_pos,
-                                int offset_pos) override {
-    if (extension_id_.empty() ||
-        !HasListener(input_ime::OnSurroundingTextChanged::kEventName))
-      return;
-
-    input_ime::OnSurroundingTextChanged::SurroundingInfo info;
-    info.text = text;
-    info.focus = cursor_pos;
-    info.anchor = anchor_pos;
-    info.offset = offset_pos;
-    scoped_ptr<base::ListValue> args(
-        input_ime::OnSurroundingTextChanged::Create(component_id, info));
-
-    DispatchEventToExtension(
-        extensions::events::INPUT_IME_ON_SURROUNDING_TEXT_CHANGED,
-        input_ime::OnSurroundingTextChanged::kEventName, std::move(args));
-  }
-
   void OnCompositionBoundsChanged(
       const std::vector<gfx::Rect>& bounds) override {
     if (extension_id_.empty() ||
@@ -261,7 +221,7 @@ class ImeObserverChromeOS : public ui::ImeObserver {
   // The component IME extensions need to know the current screen type (e.g.
   // lock screen, login screen, etc.) so that its on-screen keyboard page
   // won't open new windows/pages. See crbug.com/395621.
-  std::string GetCurrentScreenType() {
+  std::string GetCurrentScreenType() override {
     switch (chromeos::input_method::InputMethodManager::Get()
                 ->GetUISessionState()) {
       case chromeos::input_method::InputMethodManager::STATE_LOGIN_SCREEN: