Add suggestion to use "no-cors" with Fetch fails CORS check.

Source/core/fetch/CrossOriginAccessControl.cpp

Index: Source/core/fetch/CrossOriginAccessControl.cpp
diff --git a/Source/core/fetch/CrossOriginAccessControl.cpp b/Source/core/fetch/CrossOriginAccessControl.cpp
index facfe26710166dfc10dc6b3ed726201528625284..b9a5c1350070ff4dfb01d7812b8ce532f068d8ef 100644
--- a/Source/core/fetch/CrossOriginAccessControl.cpp
+++ b/Source/core/fetch/CrossOriginAccessControl.cpp
@@ -158,6 +158,8 @@ bool passesAccessControlCheck(const ResourceResponse& response, StoredCredential
             if (isInterestingStatusCode(statusCode))
                 errorDescription.append(" The response had HTTP status code " + String::number(statusCode) + ".");
 
+            errorDescription.append(" Alternatively, if you want an opaque response, switch to The Fetch API in 'no-cors' mode.");

[hiroshige, 2015/08/28 08:24:23]

nit: s/The Fetch API/the Fetch API/

+
             return false;
         }
 
@@ -172,6 +174,7 @@ bool passesAccessControlCheck(const ResourceResponse& response, StoredCredential
                 detail = "The 'Access-Control-Allow-Origin' header has a value '" + allowOriginHeaderValue + "' that is not equal to the supplied origin.";
         }
         errorDescription = buildAccessControlFailureMessage(detail, securityOrigin);
+        errorDescription.append(" Either change the header, or, if you want an opaque response, use the Fetch API in 'no-cors' mode.");
         return false;
     }