Reviewed by Darin Adler.

        Merge cf and mac header files with same name
        https://bugs.webkit.org/show_bug.cgi?id=51916

        Since most of the code in the header files is identical, we can merge them and have #if
        USE(CFNETWORK) to separate out the network specific parts.

        * WebCore.xcodeproj/project.pbxproj:
        * platform/network/cf/AuthenticationChallenge.h:
        (WebCore::AuthenticationChallenge::sender):
        (WebCore::AuthenticationChallenge::nsURLAuthenticationChallenge):
        * platform/network/cf/ResourceError.h:
        (WebCore::ResourceError::ResourceError):
        * platform/network/cf/ResourceRequest.h:
        (WebCore::ResourceRequest::ResourceRequest):
        * platform/network/cf/ResourceResponse.h:
        (WebCore::ResourceResponse::ResourceResponse):
        * platform/network/mac/AuthenticationChallenge.h: Removed.
        * platform/network/mac/ResourceError.h: Removed.
        * platform/network/mac/ResourceRequest.h: Removed.
        * platform/network/mac/ResourceResponse.h: Removed.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@75103 268f45cc-cd09-0410-ab3c-d52691b4dbfc