Make ResourceFetcher return Resources with LoadError instead of nullptrs.

third_party/WebKit/Source/web/tests/WebFrameTest.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 7870 matching lines @@
   registerMockedHttpURLLoadWithCSP("foo.html", "manifest-src 'self'");
 
   FrameTestHelpers::WebViewHelper webViewHelper;
   webViewHelper.initializeAndLoad(m_baseURL + "foo.html");
   Document* document =
       webViewHelper.webView()->mainFrameImpl()->frame()->document();
 
   Resource* resource = fetchManifest(
       document, toKURL(m_notBaseURL + "link-manifest-fetch.json"));
 
-  EXPECT_EQ(0, resource);  // Fetching resource wasn't allowed.
+  // Fetching resource wasn't allowed.
+  ASSERT_TRUE(resource);
+  EXPECT_TRUE(resource->errorOccurred());
+  EXPECT_TRUE(resource->resourceError().isAccessCheck());
 }
 
 TEST_P(ParameterizedWebFrameTest, ManifestCSPFetchSelfReportOnly) {
   URLTestHelpers::registerMockedURLLoad(
       toKURL(m_notBaseURL + "link-manifest-fetch.json"),
       "link-manifest-fetch.json");
   registerMockedHttpURLLoadWithCSP("foo.html", "manifest-src 'self'",
                                    /* report only */ true);
 
   FrameTestHelpers::WebViewHelper webViewHelper;
@@ skipping 2258 matching lines @@
   Platform::current()->getURLLoaderMockFactory()->setLoaderDelegate(nullptr);
 
   Document* document =
       toLocalFrame(helper.webView()->page()->mainFrame())->document();
   EXPECT_TRUE(document->isImageDocument());
   EXPECT_EQ(Resource::DecodeError,
             toImageDocument(document)->cachedImage()->getStatus());
 }
 
 }  // namespace blink