content: Cleanup class/struct forward declarations

content/public/test/text_input_test_utils.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 CONTENT_PUBLIC_TEST_TEXT_INPUT_TEST_UTILS_H_
 #define CONTENT_PUBLIC_TEST_TEXT_INPUT_TEST_UTILS_H_
 
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/strings/string16.h"
 #include "ui/base/ime/text_input_mode.h"
 #include "ui/base/ime/text_input_type.h"
 
 #ifdef OS_MACOSX
 #include "content/public/browser/browser_message_filter.h"
 #endif
 
 namespace ipc {
 class Message;
 }
 
 namespace gfx {
 class Range;
 }
 
-namespace ui {
-struct CompositionUnderline;
-}
-
 namespace content {
 
 class MessageLoopRunner;
 class RenderProcessHost;
 class RenderWidgetHost;
 class RenderWidgetHostView;
 class RenderWidgetHostViewBase;
 class WebContents;
 struct TextInputState;
 
@@ skipping 186 matching lines @@
                                     const gfx::Range& range);
 
 // Returns the total count of NSWindows instances which belong to the currently
 // running NSApplication.
 size_t GetOpenNSWindowsCount();
 #endif
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_TEST_TEXT_INPUT_TEST_UTILS_H_