Moving GraphicsContext and dependencies from core to platform.

public/platform/WebLayerClient.h

 /*
  * 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 13 matching lines @@
  * 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.
  */
 
 #ifndef WebLayerClient_h
 #define WebLayerClient_h
 
+#include "WebCommon.h"
+
 namespace blink {
 
 class WebGraphicsLayerDebugInfo;
 
-class WebLayerClient {
+class BLINK_PLATFORM_EXPORT WebLayerClient {
 public:
     virtual WebString debugName(WebLayer*) = 0;
 
     // Returns a pointer to a debug info object, if one has been computed.
     // If not, returns 0. If the returned pointer is non-zero, the caller takes
     // ownership of the pointer.
     virtual WebGraphicsLayerDebugInfo* takeDebugInfo() = 0;
 
 protected:
     virtual ~WebLayerClient() { }
 };
 
 } // namespace blink
 
 #endif // WebLayerClient_h