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

Source/core/loader/DocumentLoader.cpp

Index: Source/core/loader/DocumentLoader.cpp
===================================================================
--- Source/core/loader/DocumentLoader.cpp	(revision 148582)
+++ Source/core/loader/DocumentLoader.cpp	(working copy)
@@ -275,20 +275,18 @@
         return;
 
     m_isStopping = true;
-
-    FrameLoader* frameLoader = DocumentLoader::frameLoader();
     
     if (isLoadingMainResource())
         // Stop the main resource loader and let it send the cancelled message.
-        cancelMainResourceLoad(frameLoader->cancelledError(m_request));
+        cancelMainResourceLoad(ResourceError::cancelledError(m_request.url()));
     else if (!m_resourceLoaders.isEmpty())
         // The main resource loader already finished loading. Set the cancelled error on the 
         // document and let the resourceLoaders send individual cancelled messages below.
-        setMainDocumentError(frameLoader->cancelledError(m_request));
+        setMainDocumentError(ResourceError::cancelledError(m_request.url()));
     else
         // If there are no resource loaders, we need to manufacture a cancelled message.
         // (A back/forward navigation has no resource loaders because its resources are cached.)
-        mainReceivedError(frameLoader->cancelledError(m_request));
+        mainReceivedError(ResourceError::cancelledError(m_request.url()));
     
     stopLoadingSubresources();
     
@@ -425,7 +423,7 @@
     ASSERT(!newRequest.isNull());
 
     if (!frameLoader()->checkIfFormActionAllowedByCSP(newRequest.url())) {
-        cancelMainResourceLoad(frameLoader()->cancelledError(newRequest));
+        cancelMainResourceLoad(ResourceError::cancelledError(newRequest.url()));
         return;
     }
 
@@ -436,7 +434,7 @@
         RefPtr<SecurityOrigin> redirectingOrigin = SecurityOrigin::create(redirectResponse.url());
         if (!redirectingOrigin->canDisplay(newRequest.url())) {
             FrameLoader::reportLocalLoadFailed(m_frame, newRequest.url().string());
-            cancelMainResourceLoad(frameLoader()->cancelledError(newRequest));
+            cancelMainResourceLoad(ResourceError::cancelledError(newRequest.url()));
             return;
         }
         timing()->addRedirect(redirectResponse.url(), newRequest.url());
@@ -457,7 +455,7 @@
     Frame* top = m_frame->tree()->top();
     if (top != m_frame) {
         if (!frameLoader()->mixedContentChecker()->canDisplayInsecureContent(top->document()->securityOrigin(), newRequest.url())) {
-            cancelMainResourceLoad(frameLoader()->cancelledError(newRequest));
+            cancelMainResourceLoad(ResourceError::cancelledError(newRequest.url()));
             return;
         }
     }
@@ -566,7 +564,7 @@
             frame()->document()->enforceSandboxFlags(SandboxOrigin);
             if (HTMLFrameOwnerElement* ownerElement = frame()->ownerElement())
                 ownerElement->dispatchEvent(Event::create(eventNames().loadEvent, false, false));
-            cancelMainResourceLoad(frameLoader()->cancelledError(m_request));
+            cancelMainResourceLoad(ResourceError::cancelledError(m_request.url()));
             return;
         }
     }
@@ -602,7 +600,7 @@
             // keep trying to process data from their load
 
             if (hostedByObject)
-                cancelMainResourceLoad(frameLoader()->cancelledError(m_request));
+                cancelMainResourceLoad(ResourceError::cancelledError(m_request.url()));
         }
     }
 
@@ -635,14 +633,9 @@
     frameLoader->client()->committedLoad(this, data, length);
 }
 
-ResourceError DocumentLoader::interruptedForPolicyChangeError() const
-{
-    return frameLoader()->client()->interruptedForPolicyChangeError(request());
-}
-
 void DocumentLoader::stopLoadingForPolicyChange()
 {
-    ResourceError error = interruptedForPolicyChangeError();
+    ResourceError error = frameLoader()->client()->interruptedForPolicyChangeError(m_request);
     error.setIsCancellation(true);
     cancelMainResourceLoad(error);
 }
@@ -896,6 +889,7 @@
     for (SubstituteResourceMap::const_iterator it = copy.begin(); it != end; ++it) {
         RefPtr<ResourceLoader> loader = it->key;
         SubstituteResource* resource = it->value.get();
+        ASSERT(resource);
         
         if (resource) {
             SharedBuffer* data = resource->data();
@@ -915,10 +909,6 @@
                 return;
 
             loader->didFinishLoading(0, 0);
-        } else {
-            // A null resource means that we should fail the load.
-            // FIXME: Maybe we should use another error here - something like "not in cache".
-            loader->didFail(0, loader->cannotShowURLError());
         }
     }
 }
@@ -1137,7 +1127,7 @@
 void DocumentLoader::cancelMainResourceLoad(const ResourceError& resourceError)
 {
     RefPtr<DocumentLoader> protect(this);
-    ResourceError error = resourceError.isNull() ? frameLoader()->cancelledError(m_request) : resourceError;
+    ResourceError error = resourceError.isNull() ? ResourceError::cancelledError(m_request.url()) : resourceError;
 
     m_dataLoadTimer.stop();
     if (mainResourceLoader())