Fix inconsistent naming (problem title vs. problem header).

drag_and_drop_v2/public/css/drag_and_drop.css

@@ -11,7 +11,7 @@
 
 /* Header, instruction text, etc. */
 
-.xblock--drag-and-drop .problem-header {
+.xblock--drag-and-drop .problem-title {
     display: inline-block;
     margin: 0 0 15px 0;
 }

drag_and_drop_v2/public/js/view.js

@@ -215,7 +215,7 @@
     };
 
     var mainTemplate = function(ctx) {
-        var problemTitle = ctx.show_title ? h('h2.problem-header', {innerHTML: ctx.title_html}) : null;
+        var problemTitle = ctx.show_title ? h('h2.problem-title', {innerHTML: ctx.title_html}) : null;
         var problemHeader = ctx.show_problem_header ? h('h3.title1', gettext('Problem')) : null;
         var popupSelector = 'div.popup';
         if (ctx.popup_html && !ctx.last_action_correct) {

tests/integration/test_title_and_question.py

@@ -52,8 +52,8 @@ class TestDragAndDropTitleAndProblem(BaseIntegrationTest):
 
         page = self.go_to_page(const_page_name)
         if show_title:
-            problem_header = page.find_element_by_css_selector('h2.problem-header')
+            problem_header = page.find_element_by_css_selector('h2.problem-title')
             self.assertEqual(self.get_element_html(problem_header), display_name)
         else:
             with self.assertRaises(NoSuchElementException):
-                page.find_element_by_css_selector('h2.problem-header')
+                page.find_element_by_css_selector('h2.problem-title')