Clean up most of the ChromeOS headers in non-ChromeOS build

chrome/browser/ui/input_method/input_method_engine_base.h

 // Copyright 2016 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_UI_INPUT_METHOD_INPUT_METHOD_ENGINE_BASE_H_
 #define CHROME_BROWSER_UI_INPUT_METHOD_INPUT_METHOD_ENGINE_BASE_H_
 
 #include <map>
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/time/time.h"
-#include "ui/base/ime/chromeos/input_method_descriptor.h"
 #include "ui/base/ime/composition_text.h"
 #include "ui/base/ime/ime_engine_handler_interface.h"
 #include "url/gurl.h"
 
+#if defined(OS_CHROMEOS)
+#include "ui/base/ime/chromeos/input_method_descriptor.h"
+#endif  // defined(OS_CHROMEOS)
+
 class Profile;
 
 namespace ui {
 struct CompositionText;
 class IMEEngineHandlerInterface;
 class KeyEvent;
 }  // namespace ui
 
 namespace input_method {
 
@@ skipping 208 matching lines @@
   bool commit_text_changed_;
 
   // Indicates whether the IME extension is currently handling a physical key
   // event. This is used in CommitText/UpdateCompositionText/etc.
   bool handling_key_event_;
 };
 
 }  // namespace input_method
 
 #endif  // CHROME_BROWSER_UI_INPUT_METHOD_INPUT_METHOD_ENGINE_BASE_H_