Reviewed by Adele.

    Reviewed by Adele.

        - refactoring of WebDataSource in preparation for moving a bunch of it to a new class

        - minimize WebDataSourceInternal.h to be only methods called from outside WebDataSource
        - reduce Private category implementation to be only the SPI methods
        - make new Internal and FileInternal categories which contain the
        remainder (depending on whether they are called from outside of
        WebDataSource)

        * WebView/WebDataSource.m:
        (-[WebDataSource _setMainDocumentError:]):
        (addTypesFromClass):
        (+[WebDataSource _representationClassForMIMEType:]):
        (-[WebDataSource _commitIfReady]):
        (-[WebDataSource _commitLoadWithData:]):
        (-[WebDataSource _doesProgressiveLoadWithMIMEType:]):
        (-[WebDataSource _addResponse:]):
        (-[WebDataSource _revertToProvisionalState]):
        (-[WebDataSource _mainDocumentError]):
        (-[WebDataSource _addSubframeArchives:]):
        (-[WebDataSource _fileWrapperForURL:]):
        (+[WebDataSource _repTypesAllowImageTypeOmission:]):
        (-[WebDataSource _decidePolicyForMIMEType:decisionListener:]):
        (-[WebDataSource _finishedLoading]):
        (-[WebDataSource _setResponse:]):
        (-[WebDataSource _setRequest:]):
        (-[WebDataSource _setupForReplaceByMIMEType:]):
        (-[WebDataSource _receivedMainResourceError:complete:]):
        (-[WebDataSource _mainReceivedError:complete:]):
        (-[WebDataSource _defersCallbacks]):
        (-[WebDataSource _downloadWithLoadingConnection:request:response:proxy:]):
        (-[WebDataSource _didFailLoadingWithError:forResource:]):
        (-[WebDataSource _didFinishLoadingForResource:]):
        (-[WebDataSource _didReceiveData:contentLength:forResource:]):
        (-[WebDataSource _didReceiveResponse:forResource:]):
        (-[WebDataSource _didCancelAuthenticationChallenge:forResource:]):
        (-[WebDataSource _didReceiveAuthenticationChallenge:forResource:]):
        (-[WebDataSource _willSendRequest:forResource:redirectResponse:]):
        (-[WebDataSource _identifierForInitialRequest:]):
        (-[WebDataSource _archivedSubresourceForURL:]):
        (-[WebDataSource _startLoading]):
        (-[WebDataSource _stopRecordingResponses]):
        (-[WebDataSource _loadingStartedTime]):
        (-[WebDataSource _replaceSelectionWithArchive:selectReplacement:]):
        (-[WebDataSource _documentFragmentWithArchive:]):
        (-[WebDataSource _documentFragmentWithImageResource:]):
        (-[WebDataSource _imageElementWithImageResource:]):
        (-[WebDataSource _title]):
        (-[WebDataSource _isStopping]):
        (-[WebDataSource _setWebFrame:]):
        (-[WebDataSource _URL]):
        (-[WebDataSource _loadFromPageCache:]):
        (-[WebDataSource _popSubframeArchiveWithName:]):
        (-[WebDataSource _setIsClientRedirect:]):
        (-[WebDataSource _setURL:]):
        (-[WebDataSource _setLastCheckedRequest:]):
        (-[WebDataSource _defersCallbacksChanged]):
        (-[WebDataSource _lastCheckedRequest]):
        (-[WebDataSource _stopLoading]):
        (-[WebDataSource _bridge]):
        (-[WebDataSource _webView]):
        (-[WebDataSource _triggeringAction]):
        (-[WebDataSource _setTriggeringAction:]):
        (-[WebDataSource __adoptRequest:]):
        (-[WebDataSource _isDocumentHTML]):
        (-[WebDataSource _stopLoadingWithError:]):
        (-[WebDataSource _setPrimaryLoadComplete:]):
        (-[WebDataSource _responses]):
        (-[WebDataSource _makeRepresentation]):
        (-[WebDataSource _isClientRedirect]):
        (-[WebDataSource _originalRequest]):
        (-[WebDataSource _URLForHistory]):
        (-[WebDataSource _addToUnarchiveState:]):
        (-[WebDataSource _setOverrideEncoding:]):
        (-[WebDataSource _setIconURL:]):
        (-[WebDataSource _setIconURL:withType:]):
        (-[WebDataSource _overrideEncoding]):
        (-[WebDataSource _setTitle:]):
        * WebView/WebDataSourceInternal.h:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@16003 268f45cc-cd09-0410-ab3c-d52691b4dbfc