Build chrome.input.ime.* API in GN mode.

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

 // Copyright 2015 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.
 
 // This file is for non-chromeos (win & linux) functions, such as
 // chrome.input.ime.activate, chrome.input.ime.createWindow and
 // chrome.input.ime.onSelectionChanged.
 // TODO(azurewei): May refactor the code structure by using delegate or
 // redesign the API to remove this platform-specific file in the future.
 
@@ skipping 35 matching lines @@
     extensions::EventRouter::Get(profile_)
         ->DispatchEventToExtension(extension_id_, std::move(event));
   }
 
   DISALLOW_COPY_AND_ASSIGN(ImeObserverNonChromeOS);
 };
 
 }  // namespace
 
 namespace extensions {
+void InputImeAPI::OnExtensionLoaded(content::BrowserContext* browser_context,
+                                    const Extension* extension) {}
 
-bool InputImeEventRouter::RegisterImeExtension(
-    const std::string& extension_id,
-    const std::vector<extensions::InputComponentInfo>& input_components) {
-  return false;
-}
+void InputImeAPI::OnExtensionUnloaded(content::BrowserContext* browser_context,
+                                      const Extension* extension,
+                                      UnloadedExtensionInfo::Reason reason) {}
 
-void InputImeEventRouter::UnregisterAllImes(const std::string& extension_id) {}
+void InputImeAPI::OnListenerAdded(const EventListenerInfo& details) {}
 
 }  // namespace extensions