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

Source/WebCore/loader/ResourceLoader.cpp

Index: Source/WebCore/loader/ResourceLoader.cpp
===================================================================
--- Source/WebCore/loader/ResourceLoader.cpp	(revision 148494)
+++ Source/WebCore/loader/ResourceLoader.cpp	(working copy)
@@ -32,6 +32,7 @@
 
 #include "ApplicationCacheHost.h"
 #include "CachedResourceLoader.h"
+#include "CancelledResourceError.h"
 #include "DocumentLoader.h"
 #include "Frame.h"
 #include "FrameLoader.h"
@@ -295,7 +296,7 @@
     if (m_reachedTerminalState)
         return;
        
-    ResourceError nonNullError = error.isNull() ? cancelledError() : error;
+    ResourceError nonNullError = error.isNull() ? CancelledResourceError(m_request.url()) : error;

[darin (slow to review), 2013/04/17 18:58:11]

I think some compilers will actually complain here since the type of
CancelledResourceError and |error| are different.  Probably another reason why
it would be good to change to a function that returns ResourceError.

Since we have excluded policy change error, I'm now wondering if it should be:

  cancelledResourceError(failingURL)

or:

  ResourceError::cancelledError(failingURL);

Maybe the latter is better since cancellation is a concept known to
ResourceError, and this would provide a canonical way to construct a
ResourceError representing cancellation.  We might even want to make the
setIsCancellation() private.

 
     // This function calls out to clients at several points that might do
     // something that causes the last reference to this object to go away.
@@ -337,16 +338,6 @@
     releaseResources();
 }
 
-ResourceError ResourceLoader::cancelledError()
-{
-    return frameLoader()->cancelledError(m_request);
-}
-
-ResourceError ResourceLoader::cannotShowURLError()
-{
-    return frameLoader()->client()->cannotShowURLError(m_request);
-}
-
 void ResourceLoader::willSendRequest(ResourceHandle*, ResourceRequest& request, const ResourceResponse& redirectResponse)
 {
     if (documentLoader()->applicationCacheHost()->maybeLoadFallbackForRedirect(this, request, redirectResponse))