Moving GraphicsContext and dependencies from core to platform.

Source/platform/graphics/BitmapImage.h

Index: Source/platform/graphics/BitmapImage.h
diff --git a/Source/core/platform/graphics/BitmapImage.h b/Source/platform/graphics/BitmapImage.h
similarity index 98%
rename from Source/core/platform/graphics/BitmapImage.h
rename to Source/platform/graphics/BitmapImage.h
index 35589f8f35f6d63dfd4ec2224d30cf1d1316b817..05ab1d50e3b98091cf55a7929401e60ef2090850 100644
--- a/Source/core/platform/graphics/BitmapImage.h
+++ b/Source/platform/graphics/BitmapImage.h
@@ -28,12 +28,12 @@
 #ifndef BitmapImage_h
 #define BitmapImage_h
 
-#include "core/platform/graphics/FrameData.h"
-#include "core/platform/graphics/Image.h"
-#include "core/platform/graphics/ImageSource.h"
 #include "platform/geometry/IntSize.h"
 #include "platform/graphics/Color.h"
+#include "platform/graphics/FrameData.h"
+#include "platform/graphics/Image.h"
 #include "platform/graphics/ImageOrientation.h"
+#include "platform/graphics/ImageSource.h"
 #include "wtf/Forward.h"
 
 namespace WebCore {
@@ -41,7 +41,7 @@ namespace WebCore {
 class NativeImageSkia;
 template <typename T> class Timer;
 
-class BitmapImage : public Image {
+class PLATFORM_EXPORT BitmapImage : public Image {
     friend class GeneratedImage;
     friend class CrossfadeGeneratedImage;
     friend class GradientGeneratedImage;