Make ResourceFetcher return Resources with LoadError instead of nullptrs.

third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp

Index: third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
diff --git a/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp b/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
index c801e88de64a6073afa00caddc625e8cb737293e..3c3063d4a1099cdc878066f235f98ca112cbfe38 100644
--- a/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
+++ b/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
@@ -432,6 +432,15 @@ Resource* ResourceFetcher::resourceForStaticData(
   return resource;
 }
 
+Resource* ResourceFetcher::resourceForBlockedRequest(
+    const FetchRequest& request,
+    const ResourceFactory& factory) {
+  Resource* resource = factory.create(request.resourceRequest(),
+                                      request.options(), request.charset());
+  resource->error(ResourceError::cancelledDueToAccessCheckError(request.url()));
+  return resource;
+}
+
 void ResourceFetcher::moveCachedNonBlockingResourceToBlocking(
     Resource* resource,
     const FetchRequest& request) {
@@ -495,8 +504,10 @@ Resource* ResourceFetcher::requestResource(
           factory.type(), request.resourceRequest(),
           MemoryCache::removeFragmentIdentifierIfNeeded(request.url()),
           request.options(), request.forPreload(),
-          request.getOriginRestriction()))
-    return nullptr;
+          request.getOriginRestriction())) {
+    DCHECK(!substituteData.forceSynchronousLoad());
+    return resourceForBlockedRequest(request, factory);
+  }
 
   unsigned long identifier = createUniqueIdentifier();
   request.mutableResourceRequest().setPriority(computeLoadPriority(