Fix event targeting for sub-windows of system modal windows in mus+ash.

services/ui/ws/modal_window_controller.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 "services/ui/ws/modal_window_controller.h"
 
 #include "base/memory/ptr_util.h"
 #include "base/stl_util.h"
 #include "services/ui/ws/event_dispatcher.h"
 #include "services/ui/ws/server_window.h"
@@ skipping 60 matching lines @@
   if (modal_window->transient_parent() &&
       !modal_window->transient_parent()->Contains(window)) {
     return false;
   }
 
   return true;
 }
 
 bool ModalWindowController::IsWindowBlocked(const ServerWindow* window) const {
   DCHECK(window);
-  return GetActiveSystemModalWindow() || GetModalChildForWindowAncestor(window);
+  return GetTargetForWindow(window) != window;
 }
 
 const ServerWindow* ModalWindowController::GetTargetForWindow(
     const ServerWindow* window) const {
-  // TODO(moshayedi): crbug.com/697127. Handle windows which are modal to
-  // children of their transient parent.
+  // TODO(moshayedi): crbug.com/697127. Handle MODAL_TYPE_CHILD.
   ServerWindow* system_modal_window = GetActiveSystemModalWindow();
   if (system_modal_window)
-    return system_modal_window;
+    return system_modal_window->Contains(window) ? window : system_modal_window;
+
   return window ? GetWindowModalTargetForWindow(window) : nullptr;
 }
 
 ServerWindow* ModalWindowController::GetActiveSystemModalWindow() const {
   for (auto it = system_modal_windows_.rbegin();
        it != system_modal_windows_.rend(); it++) {
     ServerWindow* modal = *it;
     if (modal->IsDrawn())
       return modal;
   }
@@ skipping 18 matching lines @@
   // Move the most recently shown window to the end of the list.
   auto it = std::find(system_modal_windows_.begin(),
                       system_modal_windows_.end(), window);
   DCHECK(it != system_modal_windows_.end());
   system_modal_windows_.splice(system_modal_windows_.end(),
                                system_modal_windows_, it);
 }
 
 }  // namespace ws
 }  // namespace ui