Allow component IME extension use app.window and add 'ime' window type for app window

extensions/browser/app_window/app_window.h

 // Copyright 2014 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 EXTENSIONS_BROWSER_APP_WINDOW_APP_WINDOW_H_
 #define EXTENSIONS_BROWSER_APP_WINDOW_APP_WINDOW_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 132 matching lines @@
     CreateParams();
     ~CreateParams();
 
     WindowType window_type;
     Frame frame;
 
     bool has_frame_color;
     SkColor active_frame_color;
     SkColor inactive_frame_color;
     bool alpha_enabled;
+    bool is_ime_window;
 
     // The initial content/inner bounds specification (excluding any window
     // decorations).
     BoundsSpecification content_spec;
 
     // The initial window/outer bounds specification (including window
     // decorations).
     BoundsSpecification window_spec;
 
     std::string window_key;
@@ skipping 396 matching lines @@
 
   // Whether |alpha_enabled| was set in the CreateParams.
   bool requested_alpha_enabled_;
 
   DISALLOW_COPY_AND_ASSIGN(AppWindow);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_APP_WINDOW_APP_WINDOW_H_