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

Source/WebCore/loader/DocumentLoader.cpp

Index: Source/WebCore/loader/DocumentLoader.cpp
===================================================================
--- Source/WebCore/loader/DocumentLoader.cpp	(revision 148494)
+++ Source/WebCore/loader/DocumentLoader.cpp	(working copy)
@@ -34,6 +34,7 @@
 #include "ArchiveResourceCollection.h"
 #include "CachedPage.h"
 #include "CachedResourceLoader.h"
+#include "CancelledResourceError.h"
 #include "DOMWindow.h"
 #include "Document.h"
 #include "DocumentParser.h"
@@ -276,20 +277,18 @@
         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(CancelledResourceError(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(CancelledResourceError(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(CancelledResourceError(m_request.url()));
     
     stopLoadingSubresources();
     
@@ -426,7 +425,7 @@
     ASSERT(!newRequest.isNull());
 
     if (!frameLoader()->checkIfFormActionAllowedByCSP(newRequest.url())) {
-        cancelMainResourceLoad(frameLoader()->cancelledError(newRequest));
+        cancelMainResourceLoad(CancelledResourceError(newRequest.url()));
         return;
     }
 
@@ -437,7 +436,7 @@
         RefPtr<SecurityOrigin> redirectingOrigin = SecurityOrigin::create(redirectResponse.url());
         if (!redirectingOrigin->canDisplay(newRequest.url())) {
             FrameLoader::reportLocalLoadFailed(m_frame, newRequest.url().string());
-            cancelMainResourceLoad(frameLoader()->cancelledError(newRequest));
+            cancelMainResourceLoad(CancelledResourceError(newRequest.url()));
             return;
         }
         timing()->addRedirect(redirectResponse.url(), newRequest.url());
@@ -458,7 +457,7 @@
     Frame* top = m_frame->tree()->top();
     if (top != m_frame) {
         if (!frameLoader()->mixedContentChecker()->canDisplayInsecureContent(top->document()->securityOrigin(), newRequest.url())) {
-            cancelMainResourceLoad(frameLoader()->cancelledError(newRequest));
+            cancelMainResourceLoad(CancelledResourceError(newRequest.url()));
             return;
         }
     }
@@ -539,7 +538,7 @@
             frame()->document()->enforceSandboxFlags(SandboxOrigin);
             if (HTMLFrameOwnerElement* ownerElement = frame()->ownerElement())
                 ownerElement->dispatchEvent(Event::create(eventNames().loadEvent, false, false));
-            cancelMainResourceLoad(frameLoader()->cancelledError(m_request));
+            cancelMainResourceLoad(CancelledResourceError(m_request.url()));
             return;
         }
     }
@@ -592,8 +591,7 @@
         bool isRemoteWebArchive = equalIgnoringCase("multipart/related", mimeType)
             && !m_substituteData.isValid() && !SchemeRegistry::shouldTreatURLSchemeAsLocal(url.protocol());
         if (!frameLoader()->client()->canShowMIMEType(mimeType) || isRemoteWebArchive) {
-            frameLoader()->policyChecker()->cannotShowMIMEType(m_response);
-            // Check reachedTerminalState since the load may have already been canceled inside of _handleUnimplementablePolicyWithErrorCode::.
+            ASSERT_NOT_REACHED();
             stopLoadingForPolicyChange();
             return;
         }
@@ -601,11 +599,7 @@
     }
 
     case PolicyDownload: {
-        // m_mainResource can be null, e.g. when loading a substitute resource from application cache.
-        if (!m_mainResource) {
-            mainReceivedError(frameLoader()->client()->cannotShowURLError(m_request));
-            return;
-        }
+        ASSERT(m_mainResource);
         InspectorInstrumentation::continueWithPolicyDownload(m_frame, this, mainResourceLoader()->identifier(), m_response);
 
         // When starting the request, we didn't know that it would result in download and not navigation. Now we know that main document URL didn't change.
@@ -632,7 +626,7 @@
             // keep trying to process data from their load
 
             if (hostedByObject)
-                cancelMainResourceLoad(frameLoader()->cancelledError(m_request));
+                cancelMainResourceLoad(CancelledResourceError(m_request.url()));
         }
     }
 
@@ -665,14 +659,9 @@
     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);
 }
@@ -926,6 +915,7 @@
     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();
@@ -945,10 +935,6 @@
                 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());
         }
     }
 }
@@ -1167,7 +1153,7 @@
 void DocumentLoader::cancelMainResourceLoad(const ResourceError& resourceError)
 {
     RefPtr<DocumentLoader> protect(this);
-    ResourceError error = resourceError.isNull() ? frameLoader()->cancelledError(m_request) : resourceError;
+    ResourceError error = resourceError.isNull() ? CancelledResourceError(m_request.url()) : resourceError;
 
     m_dataLoadTimer.stop();
     if (m_waitingForContentPolicy) {