DevTools: NetworkPanel: detect iframe (parser) initiator.

LayoutTests/http/tests/inspector/console-resource-errors-expected.txt

Index: LayoutTests/http/tests/inspector/console-resource-errors-expected.txt
diff --git a/LayoutTests/http/tests/inspector/console-resource-errors-expected.txt b/LayoutTests/http/tests/inspector/console-resource-errors-expected.txt
index 3e00e21a40a98c4e232cd75e23c273f1a871955d..9a79b9e300f0283c12fb6ec7c21a8d35942fa018 100644
--- a/LayoutTests/http/tests/inspector/console-resource-errors-expected.txt
+++ b/LayoutTests/http/tests/inspector/console-resource-errors-expected.txt
@@ -4,7 +4,7 @@ Tests that errors to load a resource cause error messages to be logged to consol
 
 console-resource-errors-iframe.html:3 GET http://127.0.0.1:8000/inspector/missing.css 404 (Not Found) console-message console-error-level
 console-resource-errors-iframe.html:4 GET http://127.0.0.1:8000/inspector/non-existent-script.js 404 (Not Found) console-message console-error-level
+console-resource-errors-iframe.html:8 GET http://127.0.0.1:8000/inspector/non-existent-iframe.html 404 (Not Found) console-message console-error-level
 console-resource-errors.html:17 Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check http://xhr.spec.whatwg.org/. console-message console-warning-level
 console-resource-errors.html:18 GET http://127.0.0.1:8000/inspector/non-existent-xhr 404 (Not Found)console-resource-errors.html:18 loadXHRconsole-resource-errors.html:10 performActionsVM:1 (anonymous function) InjectedScript._evaluateOn InjectedScript._evaluateAndWrap InjectedScript.evaluate console-message console-error-level
-non-existent-iframe.html:1 GET http://127.0.0.1:8000/inspector/non-existent-iframe.html 404 (Not Found) console-message console-error-level