- move more code from WebDataSource to WebFrameLoader
        
        Also marked a few more methods in WebDataSource as likely MOVABLE in a future round, since they do not
        use any of WebDataSource's private data.

        * Loader/WebFrameLoader.h:
        * Loader/WebFrameLoader.m:
        (-[WebFrameLoader addPlugInStreamLoader:]):
        (-[WebFrameLoader removePlugInStreamLoader:]):
        (-[WebFrameLoader addSubresourceLoader:]):
        (-[WebFrameLoader removeSubresourceLoader:]):
        (-[WebFrameLoader _didReceiveAuthenticationChallenge:forResource:]):
        (-[WebFrameLoader _didCancelAuthenticationChallenge:forResource:]):
        (-[WebFrameLoader _didReceiveResponse:forResource:]):
        (-[WebFrameLoader _didReceiveData:contentLength:forResource:]):
        (-[WebFrameLoader _didFinishLoadingForResource:]):
        (-[WebFrameLoader _didFailLoadingWithError:forResource:]):
        (-[WebFrameLoader _privateBrowsingEnabled]):
        (-[WebFrameLoader _finishedLoadingResource]):
        (-[WebFrameLoader _receivedError:]):
        (-[WebFrameLoader _finishedLoading]):
        * Loader/WebMainResourceLoader.m:
        (-[WebMainResourceLoader didReceiveData:lengthReceived:allAtOnce:]):
        (-[WebMainResourceLoader didFinishLoading]):
        * Loader/WebNetscapePlugInStreamLoader.m:
        (-[WebNetscapePlugInStreamLoader didFinishLoading]):
        (-[WebNetscapePlugInStreamLoader didFailWithError:]):
        (-[WebNetscapePlugInStreamLoader cancelWithError:]):
        * Loader/WebSubresourceLoader.m:
        (+[WebSubresourceLoader startLoadingResource:withRequest:customHeaders:referrer:forFrameLoader:]):
        (-[WebSubresourceLoader signalFinish]):
        (-[WebSubresourceLoader didFailWithError:]):
        (-[WebSubresourceLoader cancel]):
        * Plugins/WebNetscapePluginStream.m:
        (-[WebNetscapePluginStream start]):
        * WebView/WebDataSource.m:
        (-[WebDataSource _replaceSelectionWithArchive:selectReplacement:]):
        (-[WebDataSource _updateIconDatabaseWithURL:]):
        (-[WebDataSource _loadIcon]):
        (-[WebDataSource _setPrimaryLoadComplete:]):
        (-[WebDataSource _cancelledError]):
        (+[WebDataSource _repTypesAllowImageTypeOmission:]):
        (+[WebDataSource _representationClassForMIMEType:]):
        (-[WebDataSource _commitLoadWithData:]):
        (-[WebDataSource _receivedMainResourceError:complete:]):
        (-[WebDataSource _iconLoaderReceivedPageIcon:]):
        (-[WebDataSource _isDocumentHTML]):
        * WebView/WebDataSourceInternal.h:



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@15962 268f45cc-cd09-0410-ab3c-d52691b4dbfc