Prevent drag-and-drop events from firing over cross-site, same-page frames.

chrome/browser/ui/views/drag_and_drop_interactive_uitest.cc

 // 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.
 
 #include <algorithm>
 #include <initializer_list>
 #include <memory>
 #include <string>
 #include <vector>
 
@@ skipping 1121 matching lines @@
   EXPECT_EQ(
       0, state->left_frame_events_counter->GetNumberOfReceivedEvents("drop"));
 
   // No events should have fired in the right frame, because it is cross-site
   // from the source of the drag.  This is the essence of this test.
   EXPECT_EQ(0, state->right_frame_events_counter->GetNumberOfReceivedEvents(
                    {"dragstart", "dragleave", "dragenter", "dragover", "drop",
                     "dragend"}));
 }
 
+// TODO(paulmeyer): Should test the case of navigation happening in the middle
+// of a drag operation, and cross-site drags should be allowed across a
+// navigation.
+
 INSTANTIATE_TEST_CASE_P(
     SameSiteSubframe, DragAndDropBrowserTest, ::testing::Values(false));
 
 INSTANTIATE_TEST_CASE_P(
     CrossSiteSubframe, DragAndDropBrowserTest, ::testing::Values(true));
 
 }  // namespace chrome