Create errors (especially cancellation errors) internally to WebCore, rather

Source/core/loader/FrameLoaderClient.h

Index: Source/core/loader/FrameLoaderClient.h
===================================================================
--- Source/core/loader/FrameLoaderClient.h	(revision 148828)
+++ Source/core/loader/FrameLoaderClient.h	(working copy)
@@ -126,8 +126,6 @@
         virtual PolicyAction policyForNewWindowAction(const NavigationAction&, const String& frameName) = 0;
         virtual PolicyAction decidePolicyForNavigationAction(const NavigationAction&, const ResourceRequest&) = 0;
 
-        virtual void dispatchUnableToImplementPolicy(const ResourceError&) = 0;
-
         virtual void dispatchWillRequestResource(CachedResourceRequest*) { }
 
         virtual void dispatchWillSendSubmitEvent(PassRefPtr<FormState>) = 0;
@@ -168,17 +166,7 @@
         virtual void didRunInsecureContent(SecurityOrigin*, const KURL&) = 0;
         virtual void didDetectXSS(const KURL&, bool didBlockEntirePage) = 0;
 
-        virtual ResourceError cancelledError(const ResourceRequest&) = 0;
-        virtual ResourceError cannotShowURLError(const ResourceRequest&) = 0;
         virtual ResourceError interruptedForPolicyChangeError(const ResourceRequest&) = 0;
-
-        virtual ResourceError cannotShowMIMETypeError(const ResourceResponse&) = 0;
-        virtual ResourceError fileDoesNotExistError(const ResourceResponse&) = 0;
-        virtual ResourceError pluginWillHandleLoadError(const ResourceResponse&) = 0;
-
-        virtual bool shouldFallBack(const ResourceError&) = 0;
-
-        virtual bool canHandleRequest(const ResourceRequest&) const = 0;
         virtual bool canShowMIMEType(const String& MIMEType) const = 0;
         virtual String generatedMIMETypeForURLScheme(const String& URLScheme) const = 0;