Added UMA statistics for changing the active window via click or touch events.

ui/views/widget/desktop_aura/desktop_native_widget_aura.h

Index: ui/views/widget/desktop_aura/desktop_native_widget_aura.h
diff --git a/ui/views/widget/desktop_aura/desktop_native_widget_aura.h b/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
index e92aa8404a80f5d75ec41cab3b3d87c343f0d601..2c172e16c5003ba6b0d93ff1d0a58d5de31ddbe5 100644
--- a/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
+++ b/ui/views/widget/desktop_aura/desktop_native_widget_aura.h
@@ -25,8 +25,8 @@ class DragDropClient;
 class FocusClient;
 class ScreenPositionClient;
 class WindowTreeClient;
-}
-}
+}  // namespace client
+}  // namespace aura
 
 namespace wm {
 class CompoundEventFilter;
@@ -35,13 +35,14 @@ class FocusController;
 class InputMethodEventFilter;
 class ShadowController;
 class VisibilityController;
+class WindowActivationPreTargetHandler;
 class WindowModalityController;
-}
+}  // namespace wm
 
 namespace views {
 namespace corewm {
 class TooltipController;
-}
+}  // namespace corewm
 class DesktopCaptureClient;
 class DesktopDispatcherClient;
 class DesktopEventClient;
@@ -266,6 +267,8 @@ class VIEWS_EXPORT DesktopNativeWidgetAura
 
   internal::NativeWidgetDelegate* native_widget_delegate_;
 
+  scoped_ptr<wm::WindowActivationPreTargetHandler>
+      window_activation_pretarget_handler_;
   scoped_ptr<wm::FocusController> focus_client_;
   scoped_ptr<DesktopDispatcherClient> dispatcher_client_;
   scoped_ptr<aura::client::ScreenPositionClient> position_client_;