Don't send touch events to windows like menus when the touch occurs outside the menu bounds.

ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc

Index: ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
index b42c5588f690932ca73ff3b5cbcfebe98703c4da..de99a8e57f9d8b351fb633ca6b72e013a4d33032 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
@@ -96,6 +96,9 @@ DesktopWindowTreeHostWin::~DesktopWindowTreeHostWin() {
 
 // static
 aura::Window* DesktopWindowTreeHostWin::GetContentWindowForHWND(HWND hwnd) {
+  // All HWND's we create should have WindowTreeHost instances associated with
+  // them. There are exceptions like the content layer creating HWND's which
+  // are not associated with WindowTreeHost instances.
   aura::WindowTreeHost* host =
       aura::WindowTreeHost::GetForAcceleratedWidget(hwnd);
   return host ? host->window()->GetProperty(kContentWindowForRootWindow) : NULL;