Bug 599966: Null check argument of window.createBlobURL to avoid crashing. r=sicking a=blocking-beta-8

--HG--
rename : content/base/test/test_bug543870.html => content/base/test/test_mozfiledataurl.html
extra : rebase_source : 43ce51487370b415340cb18de74e5bf0e718067f

content/base/test/test_mozfiledataurl.html

@@ -21,6 +21,10 @@
 <pre id="test">
 <script class="testbody" type="application/javascript;version=1.8">
 
+try {
+  createBlobURL(undefined);
+} catch(e) { }
+
 window.addEventListener("message", function(e) {
   gen.send(JSON.parse(e.data));
 }, false);

dom/base/nsGlobalWindow.cpp

@@ -3068,6 +3068,8 @@ nsGlobalWindow::CreateBlobURL(nsIDOMFile* aFile, nsAString& aURL)
 
   NS_ENSURE_STATE(mDoc);
 
+  NS_ENSURE_ARG_POINTER(aFile);
+
   nsresult rv = aFile->GetInternalUrl(mDoc->NodePrincipal(), aURL);
   NS_ENSURE_SUCCESS(rv, rv);