Prefer to forward-declare GraphicsContext in headers.

Source/platform/graphics/GraphicsContext.cpp

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "platform/graphics/GraphicsContext.h"
 
+#include "platform/TraceEvent.h"
 #include "platform/geometry/IntRect.h"
 #include "platform/geometry/RoundedRect.h"
 #include "platform/graphics/BitmapImage.h"
 #include "platform/graphics/DisplayList.h"
 #include "platform/graphics/Gradient.h"
 #include "platform/graphics/ImageBuffer.h"
 #include "platform/text/BidiResolver.h"
 #include "platform/text/TextRunIterator.h"
 #include "platform/weborigin/KURL.h"
 #include "third_party/skia/include/core/SkAnnotation.h"
@@ skipping 1770 matching lines @@
         SkPreMultiplyARGB(0x60, 0xC0, 0xC0, 0xC0)  // More transparent gray
     };
 
     return colors[index];
 }
 #endif
 
 void GraphicsContext::didDrawTextInRect(const SkRect& textRect)
 {
     if (m_trackTextRegion) {
-        TRACE_EVENT0("skia", "PlatformContextSkia::trackTextRegion");
+        TRACE_EVENT0("skia", "GraphicsContext::didDrawTextInRect");
         m_textRegion.join(textRect);
     }
 }
 
 }