Add ability to submit a form using javascript.

ios/web/public/test/web_view_interaction_test_util.mm

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/web/public/test/web_view_interaction_test_util.h"
 
 #import <Foundation/Foundation.h>
 
 #include "ios/testing/earl_grey/wait_util.h"
 #import "ios/web/web_state/ui/crw_web_controller.h"
 #include "ios/web/web_state/web_state_impl.h"
 
 using web::NavigationManager;
 
 namespace web {
 namespace test {
 
-enum ElementAction { ELEMENT_ACTION_CLICK, ELEMENT_ACTION_FOCUS };
+enum ElementAction {
+  ELEMENT_ACTION_CLICK,
+  ELEMENT_ACTION_FOCUS,
+  ELEMENT_ACTION_SUBMIT

[Eugene But (OOO till 7-30), 2016/08/26 21:48:05]

Optional NIT: Maybe add comma after last item to make suture changes cleaned?

[edchin, 2016/08/26 22:26:54]

I followed the convention already on the page. Seems reasonable to keep as is. 

+};
 
 // Returns whether the Javascript action specified by |action| ran on
 // |element_id| in the passed |web_state|.
 bool RunActionOnWebViewElementWithId(web::WebState* web_state,
                                      const std::string& element_id,
                                      ElementAction action) {
   CRWWebController* web_controller =
       static_cast<WebStateImpl*>(web_state)->GetWebController();
   const char* js_action = nullptr;
   switch (action) {
     case ELEMENT_ACTION_CLICK:
       js_action = ".click()";
       break;
     case ELEMENT_ACTION_FOCUS:
       js_action = ".focus();";
       break;
+    case ELEMENT_ACTION_SUBMIT:
+      js_action = ".submit();";
+      break;
   }
   NSString* script = [NSString
       stringWithFormat:@"(function() {"
                         "  var element = document.getElementById('%s');"
                         "  if (element) {"
                         "    element%s;"
                         "    return true;"
                         "  }"
                         "  return false;"
                         "})();",
@@ skipping 18 matching lines @@
   return RunActionOnWebViewElementWithId(web_state, element_id,
                                          ELEMENT_ACTION_CLICK);
 }
 
 bool FocusWebViewElementWithId(web::WebState* web_state,
                                const std::string& element_id) {
   return RunActionOnWebViewElementWithId(web_state, element_id,
                                          ELEMENT_ACTION_FOCUS);
 }
 
+bool SubmitWebViewFormWithId(web::WebState* web_state,
+                             const std::string& form_id) {
+  return RunActionOnWebViewElementWithId(web_state, form_id,
+                                         ELEMENT_ACTION_SUBMIT);
+}
+
 }  // namespace test
 }  // namespace web