Attempt at implementing file upload progress

src/ng/http.js

@@ -977,7 +977,7 @@ function $HttpProvider() {
       // if we won't have the response in cache, send the request to the backend
       if (isUndefined(cachedResp)) {
         $httpBackend(config.method, url, reqData, done, reqHeaders, config.timeout,
-            config.withCredentials, config.responseType);
+            config.withCredentials, config.responseType, notify);
       }
 
       return promise;
@@ -1004,6 +1004,16 @@ function $HttpProvider() {
       }
 
 
+      /**
+       * Callback registered to $httpBackend():
+       *  - propagates xhr events via notify
+       *  - calls $apply
+       */
+      function notify(event) {
+        deferred.notify(event);
+        if (!$rootScope.$$phase) $rootScope.$apply();
+      }
+
       /**
        * Resolves the raw $http promise.
        */

src/ng/httpBackend.js

@@ -36,7 +36,7 @@ function createHttpBackend($browser, createXhr, $browserDefer, callbacks, rawDoc
   var ABORTED = -1;
 
   // TODO(vojta): fix the signature
-  return function(method, url, post, callback, headers, timeout, withCredentials, responseType) {
+  return function(method, url, post, callback, headers, timeout, withCredentials, responseType, notifyCallback) {
     var status;
     $browser.$$incOutstandingRequestCount();
     url = url || $browser.url();
@@ -97,6 +97,10 @@ function createHttpBackend($browser, createXhr, $browserDefer, callbacks, rawDoc
         }
       };
 
+      xhr.upload.onprogress = function(e) {
+        notifyCallback(e);
+      };
+
       if (withCredentials) {
         xhr.withCredentials = true;
       }

src/ngMock/angular-mocks.js

@@ -1653,6 +1653,8 @@ function MockXhr() {
     return lines.join('\n');
   };
 
+  this.upload = {};
+
   this.abort = angular.noop;
 }
 

test/ng/httpBackendSpec.js

@@ -245,6 +245,8 @@ describe('$httpBackend', function() {
       };
 
       this.getAllResponseHeaders = valueFn('');
+
+      this.upload = {};
     }
 
     callback.andCallFake(function(status, response) {