Reviewed by Adele (preliminary version) and later by Kevin.

    Reviewed by Adele (preliminary version) and later by Kevin.

        - remove most WebKit dependencies from WebMainResourceLoader.

        * Loader/WebFrameLoader.h:
        * Loader/WebFrameLoader.m:
        (-[WebFrameLoader cannotShowMIMETypeForURL:]):
        (-[WebFrameLoader interruptForPolicyChangeErrorWithRequest:]):
        (-[WebFrameLoader isHostedByObjectElement]):
        (-[WebFrameLoader isLoadingMainFrame]):
        (+[WebFrameLoader _canShowMIMEType:]):
        (+[WebFrameLoader _representationExistsForURLScheme:]):
        (+[WebFrameLoader _generatedMIMETypeForURLScheme:]):
        * Loader/WebMainResourceLoader.h:
        * Loader/WebMainResourceLoader.m:
        (-[WebMainResourceLoader interruptForPolicyChangeError]):
        (-[WebMainResourceLoader willSendRequest:redirectResponse:]):
        (isCaseInsensitiveEqual):
        (shouldLoadAsEmptyDocument):
        (-[WebMainResourceLoader continueAfterContentPolicy:response:]):
        (-[WebMainResourceLoader didReceiveResponse:]):
        (-[WebMainResourceLoader didReceiveData:lengthReceived:allAtOnce:]):
        (-[WebMainResourceLoader didFinishLoading]):
        (-[WebMainResourceLoader loadWithRequestNow:]):
        (-[WebMainResourceLoader loadWithRequest:]):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@15903 268f45cc-cd09-0410-ab3c-d52691b4dbfc