Split the CSSParserContext class out of CSSParserMode into its own file.

third_party/WebKit/Source/core/paint/BoxPainter.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 BoxPainter_h
 #define BoxPainter_h
 
 #include "core/layout/BackgroundBleedAvoidance.h"
 #include "core/style/ShadowData.h"
 #include "platform/geometry/LayoutSize.h"
 #include "platform/graphics/GraphicsTypes.h"
 #include "third_party/skia/include/core/SkBlendMode.h"
 #include "wtf/Allocator.h"
 
 namespace blink {
 
 class ComputedStyle;
+class Document;
 class FillLayer;
 class FloatRoundedRect;
 class GraphicsContext;
 class Image;
 class InlineFlowBox;
 class LayoutPoint;
 class LayoutRect;
 class LayoutBoxModelObject;
 class NinePieceImage;
 struct PaintInfo;
@@ skipping 94 matching lines @@
                        const LayoutRect&,
                        const Color& backgroundColor,
                        BackgroundBleedAvoidance = BackgroundBleedNone);
 
   const LayoutBox& m_layoutBox;
 };
 
 }  // namespace blink
 
 #endif