Add an error page for resources blocked via XSS Auditor.

components/test_runner/web_frame_test_client.cc

Index: components/test_runner/web_frame_test_client.cc
diff --git a/components/test_runner/web_frame_test_client.cc b/components/test_runner/web_frame_test_client.cc
index 22056d8fbb1196d3ae6327786af3a6c0f05e9b59..e6a3e700b429b2ebba895d1d69000ecdab3d1524 100644
--- a/components/test_runner/web_frame_test_client.cc
+++ b/components/test_runner/web_frame_test_client.cc
@@ -23,6 +23,7 @@
 #include "components/test_runner/web_test_delegate.h"
 #include "components/test_runner/web_view_test_proxy.h"
 #include "components/test_runner/web_widget_test_proxy.h"
+#include "net/base/net_errors.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 #include "third_party/WebKit/public/platform/WebURL.h"
 #include "third_party/WebKit/public/platform/WebURLRequest.h"
@@ -404,6 +405,13 @@ void WebFrameTestClient::loadURLExternally(
   }
 }
 
+void WebFrameTestClient::loadErrorPage(int reason) {
+  if (test_runner()->shouldDumpFrameLoadCallbacks()) {
+    delegate_->PrintMessage(base::StringPrintf(
+        "- loadErrorPage: %s\n", net::ErrorToString(reason).c_str()));
+  }
+}
+
 void WebFrameTestClient::didStartProvisionalLoad(blink::WebLocalFrame* frame) {
   test_runner()->tryToSetTopLoadingFrame(frame);