ui: Cleanup class/struct forward declarations

ui/views/animation/ink_drop_highlight.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 UI_VIEWS_ANIMATION_INK_DROP_HIGHLIGHT_H_
 #define UI_VIEWS_ANIMATION_INK_DROP_HIGHLIGHT_H_
 
 #include <iosfwd>
 #include <memory>
 
 #include "base/macros.h"
 #include "base/time/time.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/geometry/point.h"
 #include "ui/gfx/geometry/point_f.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/transform.h"
 #include "ui/views/views_export.h"
 
-namespace gfx {
-class Rect;
-}
-
 namespace ui {
 class Layer;
 class CallbackLayerAnimationObserver;
 }  // namespace ui
 
 namespace views {
 namespace test {
 class InkDropHighlightTestApi;
 }  // namespace test
 
@@ skipping 108 matching lines @@
 
 // This is declared here for use in gtest-based unit tests but is defined in
 // the views_test_support target. Depend on that to use this in your unit test.
 // This should not be used in production code - call ToString() instead.
 void PrintTo(InkDropHighlight::AnimationType animation_type,
              ::std::ostream* os);
 
 }  // namespace views
 
 #endif  // UI_VIEWS_ANIMATION_INK_DROP_HIGHLIGHT_H_