views/mus: Connect cursor events to the mus window.

content/browser/renderer_host/render_widget_host_view_aura.cc

Index: content/browser/renderer_host/render_widget_host_view_aura.cc
diff --git a/content/browser/renderer_host/render_widget_host_view_aura.cc b/content/browser/renderer_host/render_widget_host_view_aura.cc
index 51d18a0b1a43a10a6ce486dac2d2a40ee032d1b5..6a010b5b6fa522187f13ddc95888e116937a7d78 100644
--- a/content/browser/renderer_host/render_widget_host_view_aura.cc
+++ b/content/browser/renderer_host/render_widget_host_view_aura.cc
@@ -2417,11 +2417,11 @@ void RenderWidgetHostViewAura::UpdateCursorIfOverSelf() {
 
   gfx::Point cursor_screen_point = screen->GetCursorScreenPoint();
 
-#if !defined(OS_CHROMEOS)
+#if defined(OS_WIN)
   // Ignore cursor update messages if the window under the cursor is not us.
   aura::Window* window_at_screen_point = screen->GetWindowAtScreenPoint(
       cursor_screen_point);
-#if defined(OS_WIN)
+
   // On Windows we may fail to retrieve the aura Window at the current cursor
   // position. This is because the WindowFromPoint API may return the legacy
   // window which is not associated with an aura Window. In this case we need
@@ -2437,11 +2437,14 @@ void RenderWidgetHostViewAura::UpdateCursorIfOverSelf() {
     window_at_screen_point = screen_win->GetNativeWindowFromHWND(
         hwnd_at_point);
   }
-#endif
+
   if (!window_at_screen_point ||
       (window_at_screen_point->GetRootWindow() != root_window)) {
     return;
   }
+#elif !defined(OS_CHROMEOS)
+  if (!screen->IsWindowUnderCursor(window_))
+    return;
 #endif
 
   gfx::Point root_window_point = cursor_screen_point;