Fixes bugs in cursor handling

services/ui/ws/event_dispatcher.cc

 // Copyright 2015 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/event_dispatcher.h"
 
 #include <algorithm>
 
 #include "base/memory/ptr_util.h"
 #include "base/time/time.h"
@@ skipping 75 matching lines @@
   delegate_->OnMouseCursorLocationChanged(screen_location);
 }
 
 ui::mojom::Cursor EventDispatcher::GetCurrentMouseCursor() const {
   if (drag_controller_)
     return drag_controller_->current_cursor();
 
   if (!mouse_cursor_source_window_)
     return ui::mojom::Cursor::POINTER;
 
-  return mouse_cursor_in_non_client_area_
-             ? mouse_cursor_source_window_->non_client_cursor()
-             : mouse_cursor_source_window_->cursor();
+  if (mouse_cursor_in_non_client_area_)
+    return mouse_cursor_source_window_->non_client_cursor();
+
+  const ServerWindow* window = GetWindowForMouseCursor();
+  return window ? window->cursor() : ui::mojom::Cursor::POINTER;
 }
 
 bool EventDispatcher::SetCaptureWindow(ServerWindow* window,
                                        ClientSpecificId client_id) {
   if (!window)
     client_id = kInvalidClientId;
 
   if (window == capture_window_ && client_id == capture_window_client_id_)
     return true;
 
@@ skipping 82 matching lines @@
 }
 
 void EventDispatcher::ReleaseCaptureBlockedByAnyModalWindow() {
   if (!capture_window_)
     return;
 
   if (modal_window_controller_.IsWindowBlocked(capture_window_))
     SetCaptureWindow(nullptr, kInvalidClientId);
 }
 
+const ServerWindow* EventDispatcher::GetWindowForMouseCursor() const {
+  if (mouse_cursor_in_non_client_area_ || !mouse_cursor_source_window_)
+    return mouse_cursor_source_window_;
+
+  // Return the ancestor (starting at |mouse_cursor_source_window_|) whose
+  // client id differs. In other words, return the first window ancestor that is
+  // an embed root. This is done to match the behavior of aura, which sets the
+  // cursor on the root.
+  const ClientSpecificId target_client_id = delegate_->GetEventTargetClientId(
+      mouse_cursor_source_window_, mouse_cursor_in_non_client_area_);
+  const ServerWindow* window = mouse_cursor_source_window_;
+  while (window && window->id().client_id == target_client_id)
+    window = window->parent();
+  return window;
+}
+
 void EventDispatcher::UpdateNonClientAreaForCurrentWindow() {
   if (mouse_cursor_source_window_) {
     DeepestWindow deepest_window =
         FindDeepestVisibleWindowForEvents(mouse_pointer_last_location_);
     if (deepest_window.window == mouse_cursor_source_window_) {
       mouse_cursor_in_non_client_area_ = mouse_cursor_source_window_
                                              ? deepest_window.in_non_client_area
                                              : false;
     }
   }
@@ skipping 414 matching lines @@
   if (mouse_cursor_source_window_ == window)
     mouse_cursor_source_window_ = nullptr;
 }
 
 void EventDispatcher::OnDragCursorUpdated() {
   delegate_->UpdateNativeCursorFromDispatcher();
 }
 
 }  // namespace ws
 }  // namespace ui