<rdar://problem/7259965> REGRESSION: http/tests/xmlhttprequest/cross-origin-authorization.html
        is failing/crashing intermittently
        https://bugs.webkit.org/show_bug.cgi?id=29322

        This was caused by CStringBuffer::encodeBase64() returning a buffer that wasn't zero terminated.
        The code had other issues as well, so I removed it altogether:
        - it claimed to avoid some buffer copies, but it didn't;
        - and I don't think that base64 encoding should be part of CString interface.


WebCore:
        * platform/network/mac/ResourceHandleMac.mm:
        (WebCore::encodeBasicAuthorization): Encode username and password using Base64.h directly.
        (WebCore::ResourceHandle::start): Use encodeBasicAuthorization().
        (+[WebCoreSynchronousLoader loadRequest:allowStoredCredentials:returningResponse:error:]): Ditto.
        (-[WebCoreSynchronousLoader connection:willSendRequest:redirectResponse:]): Extended logging
        to synchronous case.
        (-[WebCoreSynchronousLoader connectionShouldUseCredentialStorage:]): Ditto.
        (-[WebCoreSynchronousLoader connection:didReceiveAuthenticationChallenge:]): Ditto.
        (-[WebCoreSynchronousLoader connection:didReceiveResponse:]): Ditto.
        (-[WebCoreSynchronousLoader connection:didReceiveData:]): Ditto.
        (-[WebCoreSynchronousLoader connectionDidFinishLoading:]): Ditto.
        (-[WebCoreSynchronousLoader connection:didFailWithError:]): Ditto.

        * platform/network/cf/ResourceHandleCFNet.cpp: Matched Mac changes.

        * platform/text/CString.cpp:
        * platform/text/CString.h:
        (WebCore::CStringBuffer::create):
        (WebCore::CStringBuffer::CStringBuffer):
        Removed code that was added for Base64 in r48363.

LayoutTests:
        * http/tests/xmlhttprequest/cross-origin-authorization.html: While at it, made the test
        detect more error conditions



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@48879 268f45cc-cd09-0410-ab3c-d52691b4dbfc