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

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

 // 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.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_INPUT_IME_INPUT_IME_API_CHROMEOS_H_
 #define CHROME_BROWSER_EXTENSIONS_API_INPUT_IME_INPUT_IME_API_CHROMEOS_H_
 
 #include "extensions/browser/extension_function.h"
 
 namespace extensions {
@@ skipping 120 matching lines @@
   DECLARE_EXTENSION_FUNCTION("input.ime.hideInputView",
                              INPUT_IME_HIDEINPUTVIEW)
 
  protected:
   ~InputImeHideInputViewFunction() override {}
 
   // ExtensionFunction:
   bool RunAsync() override;
 };
 
+class ExtensionRegistry;
+struct InputComponentInfo;
+
+class InputImeEventRouter {
+ public:
+  explicit InputImeEventRouter(Profile* profile);
+  ~InputImeEventRouter();
+
+  bool RegisterImeExtension(
+      const std::string& extension_id,
+      const std::vector<extensions::InputComponentInfo>& input_components);
+  void UnregisterAllImes(const std::string& extension_id);
+
+  ui::IMEEngineHandlerInterface* GetEngine(const std::string& extension_id,
+                                           const std::string& component_id);
+  ui::IMEEngineHandlerInterface* GetActiveEngine(
+      const std::string& extension_id);
+
+  // Called when a key event was handled.
+  void OnKeyEventHandled(const std::string& extension_id,
+                         const std::string& request_id,
+                         bool handled);
+
+  std::string AddRequest(

[Shu Chen, 2016/01/05 15:10:48]

I think AddRequest() and the request map logics can be shared between chromeos
and non-chromeos.

Can you please try to abstract it to a base class?

[Devlin, 2016/01/05 18:39:06]

+1.  The goal is to have these platform-specific files be as small as possible.

[Azure Wei, 2016/01/06 06:53:47]

Done. Added class InputImeEventRouterBase.

[Azure Wei, 2016/01/06 06:53:47]

Done.

+      const std::string& component_id,
+      ui::IMEEngineHandlerInterface::KeyEventDoneCallback& key_data);
+
+ private:
+  typedef std::map<
+      std::string,
+      std::pair<std::string,
+                ui::IMEEngineHandlerInterface::KeyEventDoneCallback>>
+      RequestMap;
+
+  // The engine map from extension_id to an engine.
+  std::map<std::string, ui::IMEEngineHandlerInterface*> engine_map_;
+
+  unsigned int next_request_id_;
+  RequestMap request_map_;
+  Profile* profile_;
+
+  DISALLOW_COPY_AND_ASSIGN(InputImeEventRouter);
+};
+
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_INPUT_IME_INPUT_IME_API_CHROMEOS_H_