DragImage should not depend on Frame and CachedImage
https://bugs.webkit.org/show_bug.cgi?id=21357

Reviewed by Sam Weinig.

Remove Frame and CachedImage dependencies from DragImage.

* dom/Clipboard.h:
(WebCore): Add forward delcaration for CacheImage since it's not
included anymore in DragImage.h.
* page/DragController.cpp:
(WebCore::DragController::startDrag): Use
Frame::dragImageForSelection() and call
dissolveDragImageToFraction() for the returned DragImage. Pass the
font rendering mode to createDragImageForLink, instead of a Frame
that is only used to get the font rendering mode.
(WebCore::DragController::doImageDrag): Get the suggested filename
for the cached image and pass it to
createDragImageIconForCachedImageFilename().
* platform/DragImage.cpp:
(WebCore::createDragImageForLink): Receive a FontRenderingMode
instead of a Frame.
* platform/DragImage.h:
(WebCore): Remove createDragImageForSelection, change
createDragImageForLink to receive a FontRenderingMode instead of a
frame, and rename createDragImageIconForCachedImage as
createDragImageIconForCachedImageFilename since it nows received
the suggested filename of the cached image.
* platform/blackberry/DragImageBlackBerry.cpp:
(WebCore::createDragImageIconForCachedImageFilename): Adapt to API
changes.
* platform/efl/DragImageEfl.cpp:
(WebCore::createDragImageIconForCachedImageFilename): Ditto.
* platform/gtk/DragImageGtk.cpp:
(WebCore::createDragImageIconForCachedImageFilename): Ditto.
* platform/mac/DragImageMac.mm:
(WebCore::dissolveDragImageToFraction): Return early if the passed
image is NULL.
(WebCore::createDragImageIconForCachedImageFilename): Adapt to API
changes.
(WebCore::createDragImageForLink): Ditto.
* platform/qt/DragImageQt.cpp:
(WebCore::createDragImageIconForCachedImageFilename): Ditto.
* platform/win/DragImageWin.cpp:
(WebCore::createDragImageIconForCachedImageFilename): Ditto.
(WebCore::createDragImageForLink): Ditto.
* platform/wx/DragImageWx.cpp:
(WebCore::createDragImageIconForCachedImageFilename): Ditto.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@147912 268f45cc-cd09-0410-ab3c-d52691b4dbfc