fix($browser.xhr): respond with internal -2 status on jsonp error

If jsonp is not successfull, we return internal status -2.
This internal status should by normalized by $xhr into 0,
but $xhr needs to distinguish between jsonp-error/abort/timeout (all status 0).

Author: vojtajina

src/service/browser.js

@@ -109,7 +109,7 @@ function Browser(window, document, body, XHR, $log, $sniffer) {
         if (window[callbackId].data) {
           completeOutstandingRequest(callback, 200, window[callbackId].data);
         } else {
-          completeOutstandingRequest(callback);
+          completeOutstandingRequest(callback, -2);
         }
         delete window[callbackId];
         body[0].removeChild(script);

src/service/xhr.js

@@ -165,7 +165,7 @@
            function() {
          element(':button:contains("Invalid JSONP")').click();
          element(':button:contains("fetch")').click();
-         expect(binding('code')).toBe('code=');
+         expect(binding('code')).toBe('code=-2');
          expect(binding('response')).toBe('response=Request failed');
        });
      </doc:scenario>

test/service/browserSpecs.js

@@ -147,14 +147,14 @@ describe('browser', function() {
         });
 
 
-        it('should call callback when script fails to load', function() {
+        it('should call callback with status -2 when script fails to load', function() {
           browser.xhr('JSONP', 'http://example.org/path?cb=JSON_CALLBACK', null, callback);
           var script = scripts[0];
           expect(typeof script.onload).toBe('function');
           expect(typeof script.onerror).toBe('function');
           script.onerror();
 
-          expect(log).toEqual('undefined:undefined;');
+          expect(log).toEqual('-2:undefined;');
         });