Reviewed by Adam.
        
        - Fix a crash when removing a loading media element from the tree.
        - Follow the spec by invoking pause() when element is removed from the tree instead of unloading.

        Tests: http/tests/media/remove-while-loading.html
               media/remove-from-document.html

        * html/HTMLMediaElement.cpp:
        (WebCore::HTMLMediaElement::removedFromDocument):

LayoutTests:

        Reviewed by Adam.
        
        Test that removing a media element when it is loading does not crash.
        Test that media is paused when it is removed from the tree.

        * http/tests/media/remove-while-loading-expected.txt: Added.
        * http/tests/media/remove-while-loading.html: Added.
        * media/remove-from-document-expected.txt: Added.
        * media/remove-from-document.html: Added.



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@28312 268f45cc-cd09-0410-ab3c-d52691b4dbfc