https://bugs.webkit.org/show_bug.cgi?id=62998

Reviewed by Tony Chang.

Source/WebCore:

Only select an image being dragged if it is contenteditable.

Test: fast/events/drag-selects-image.html

* dom/Node.cpp:
(WebCore::Node::isContentRichlyEditable):
* dom/Node.h:
* page/DragController.cpp:
(WebCore::prepareClipboardForImageDrag):

LayoutTests:

* fast/events/drag-selects-image-expected.txt: Added.
* fast/events/drag-selects-image.html: Added.
* platform/chromium-win/editing/pasteboard/drag-image-to-contenteditable-in-iframe-expected.txt:
* platform/chromium-win/editing/selection/drag-to-contenteditable-iframe-expected.txt:
* platform/chromium/test_expectations.txt:
* platform/mac/editing/pasteboard/drag-image-to-contenteditable-in-iframe-expected.txt:
* platform/mac/editing/selection/drag-to-contenteditable-iframe-expected.txt:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@97878 268f45cc-cd09-0410-ab3c-d52691b4dbfc