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

ui/views/controls/menu/menu_host.cc

Index: ui/views/controls/menu/menu_host.cc
diff --git a/ui/views/controls/menu/menu_host.cc b/ui/views/controls/menu/menu_host.cc
index 9840abbdf0f650848ddac72fd05b68470f8eb1bf..0707400c3d3e6781d4b6716b1ce08eb77b7d56c1 100644
--- a/ui/views/controls/menu/menu_host.cc
+++ b/ui/views/controls/menu/menu_host.cc
@@ -5,8 +5,10 @@
 #include "ui/views/controls/menu/menu_host.h"
 
 #include "base/auto_reset.h"
+#include "base/logging.h"
 #include "base/trace_event/trace_event.h"
 #include "build/build_config.h"
+#include "ui/aura/window_observer.h"
 #include "ui/events/gestures/gesture_recognizer.h"
 #include "ui/gfx/path.h"
 #include "ui/native_theme/native_theme.h"
@@ -19,8 +21,67 @@
 #include "ui/views/widget/native_widget_private.h"
 #include "ui/views/widget/widget.h"
 
+#if !defined(OS_MACOSX)
+#include "ui/aura/window.h"
+#endif
+
 namespace views {
 
+namespace internal {
+
+#if !defined(OS_MACOSX)
+// This class adds itself as the pre target handler for the |window|
+// passed in. It currently handles touch events and forwards them to the
+// controller. Reason for this approach is views does not get raw touch
+// events which we need to determine if a touch happened outside the bounds
+// of the menu.
+class PreMenuEventDispatchHandler : public ui::EventHandler,
+                                    aura::WindowObserver {
+ public:
+  explicit PreMenuEventDispatchHandler(const MenuController* controller,

[sky, 2016/01/13 16:31:13]

nit: no explict

[ananta, 2016/01/13 21:34:47]

Done.

+                                       SubmenuView* submenu,
+                                       aura::Window* window)
+      : menu_controller_(const_cast<MenuController*>(controller)),
+        submenu_(submenu),
+        window_(window) {
+    window_->AddPreTargetHandler(this);
+    window_->AddObserver(this);
+  }
+
+  ~PreMenuEventDispatchHandler() override {
+    StopObserving();
+  }
+
+  // ui::EventHandler overrides.
+  void OnTouchEvent(ui::TouchEvent* event) override {
+    menu_controller_->OnTouchEvent(submenu_, event);
+  }
+
+  // aura::WindowObserver overrides.
+  void OnWindowDestroying(aura::Window* window) override {
+    DCHECK(window_ == window);
+    StopObserving();
+  }
+
+ private:
+  void StopObserving() {
+    if (!window_)
+      return;
+    window_->RemovePreTargetHandler(this);
+    window_->RemoveObserver(this);
+    window_ = nullptr;
+  }
+
+  MenuController* menu_controller_;
+  SubmenuView* submenu_;
+  aura::Window* window_;
+
+  DISALLOW_COPY_AND_ASSIGN(PreMenuEventDispatchHandler);
+};
+#endif  // OS_MACOSX
+
+}  // namespace internal
+
 ////////////////////////////////////////////////////////////////////////////////
 // MenuHost, public:
 
@@ -61,6 +122,11 @@ void MenuHost::InitMenuHost(Widget* parent,
 #endif
   Init(params);
 
+#if !defined(OS_MACOSX)
+  pre_dispatch_handler_.reset(new internal::PreMenuEventDispatchHandler(
+      menu_controller, submenu_, GetNativeView()));
+#endif
+
   SetContentsView(contents_view);
   ShowMenuHost(do_capture);
 }
@@ -93,6 +159,9 @@ void MenuHost::DestroyMenuHost() {
   HideMenuHost();
   destroying_ = true;
   static_cast<MenuHostRootView*>(GetRootView())->ClearSubmenu();
+#if !defined(OS_MACOSX)
+  pre_dispatch_handler_.reset();
+#endif
   Close();
 }