Update debugger tests for new JSON.parse syntax error message format. Followup to bug 507998, r=yetmoreorangesigh

--HG--
extra : rebase_source : 9e4009922085b67d2ca7f8e92c7ec269c7446924

browser/devtools/netmonitor/test/browser_net_json-malformed.js

@@ -41,11 +41,11 @@ function test() {
           "The response info header doesn't have the intended visibility.");
         is(tabpanel.querySelector("#response-content-info-header")
           .getAttribute("value"),
-          "SyntaxError: JSON.parse: unexpected non-whitespace character after JSON data",
+          "SyntaxError: JSON.parse: unexpected non-whitespace character after JSON data at line 1 column 40 of the JSON data",
           "The response info header doesn't have the intended value attribute.");
         is(tabpanel.querySelector("#response-content-info-header")
           .getAttribute("tooltiptext"),
-          "SyntaxError: JSON.parse: unexpected non-whitespace character after JSON data",
+          "SyntaxError: JSON.parse: unexpected non-whitespace character after JSON data at line 1 column 40 of the JSON data",
           "The response info header doesn't have the intended tooltiptext attribute.");
 
         is(tabpanel.querySelector("#response-content-json-box")