https://bugs.webkit.org/show_bug.cgi?id=122427

Patch by Sam Weinig <sam@webkit.org> on 2013-10-07
Reviewed by Andreas Kling.

Source/WebCore:

Use references to indicate non-nullness of DragController related
objects.

Source/WebKit/efl:

* WebCoreSupport/DragClientEfl.cpp:
(WebCore::DragClientEfl::willPerformDragDestinationAction):
(WebCore::DragClientEfl::willPerformDragSourceAction):
(WebCore::DragClientEfl::actionMaskForDrag):
(WebCore::DragClientEfl::startDrag):
* WebCoreSupport/DragClientEfl.h:

Source/WebKit/gtk:

* WebCoreSupport/DragClientGtk.cpp:
(WebKit::DragClient::willPerformDragDestinationAction):
(WebKit::DragClient::willPerformDragSourceAction):
(WebKit::DragClient::actionMaskForDrag):
(WebKit::DragClient::startDrag):
* WebCoreSupport/DragClientGtk.h:
* webkit/webkitwebview.cpp:
(dragExitedCallback):
(webkit_web_view_drag_motion):
(webkit_web_view_drag_data_received):
(webkit_web_view_drag_drop):

Source/WebKit/mac:

* WebCoreSupport/WebDra...