Remove NOTIFICATION_EXTENSION_ENABLED.

chrome/browser/extensions/api/input_ime/input_ime_api.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 CHROME_BROWSER_EXTENSIONS_API_INPUT_IME_INPUT_IME_API_H_
 #define CHROME_BROWSER_EXTENSIONS_API_INPUT_IME_INPUT_IME_API_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/singleton.h"
 #include "base/scoped_observer.h"
 #include "base/values.h"
 #include "build/build_config.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/input_method/input_method_engine_base.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"

[lazyboy, 2017/05/17 18:14:48]

This was transitively being included through EventRouter.

 #include "extensions/browser/browser_context_keyed_api_factory.h"
 #include "extensions/browser/event_router.h"
 #include "extensions/browser/extension_function.h"
 #include "extensions/browser/extension_registry_observer.h"
 #include "extensions/common/extension.h"
 #include "ui/base/ime/ime_engine_handler_interface.h"
 #include "ui/base/ime/text_input_flags.h"
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/extensions/api/input_ime/input_ime_api_chromeos.h"
 #elif defined(OS_LINUX) || defined(OS_WIN)
 #include "chrome/browser/extensions/api/input_ime/input_ime_api_nonchromeos.h"
 #endif  // defined(OS_CHROMEOS)
 
 class Profile;
 
-namespace content {
-class NotificationRegistrar;
-}
-
 namespace ui {
 class IMEEngineHandlerInterface;
 
 class ImeObserver : public input_method::InputMethodEngineBase::Observer {
  public:
   ImeObserver(const std::string& extension_id, Profile* profile);
 
   ~ImeObserver() override {}
 
   // input_method::InputMethodEngineBase::Observer overrides.
@@ skipping 162 matching lines @@
       extension_registry_observer_;
 
   content::NotificationRegistrar registrar_;
 };
 
 InputImeEventRouter* GetInputImeEventRouter(Profile* profile);
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_INPUT_IME_INPUT_IME_API_H_