Add an error page for resources blocked via XSS Auditor.

third_party/WebKit/Source/core/html/parser/XSSAuditor.cpp

Index: third_party/WebKit/Source/core/html/parser/XSSAuditor.cpp
diff --git a/third_party/WebKit/Source/core/html/parser/XSSAuditor.cpp b/third_party/WebKit/Source/core/html/parser/XSSAuditor.cpp
index 165479ca8be105a7e08b2f7e75f93c4e740f0b0d..bb3b3eaf836f80fa8b406df81dd55aebff8824d6 100644
--- a/third_party/WebKit/Source/core/html/parser/XSSAuditor.cpp
+++ b/third_party/WebKit/Source/core/html/parser/XSSAuditor.cpp
@@ -359,6 +359,13 @@ void XSSAuditor::init(Document* document, XSSAuditorDelegate* auditorDelegate) {
 
   if (DocumentLoader* documentLoader =
           document->frame()->loader().documentLoader()) {
+    // We don't process error pages.
+    printf("XSSAuditor::init: '%s', '%s'\n", m_documentURL.getString().utf8().data(), documentLoader->unreachableURL().getString().utf8().data());
+    if (!documentLoader->unreachableURL().isEmpty()) {
+        m_isEnabled = false;
+        return;
+    }
+
     const AtomicString& headerValue =
         documentLoader->response().httpHeaderField(HTTPNames::X_XSS_Protection);
     String errorDetails;