Move UserActivityDetector from ash/wm/ to ui/wm/core/.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 003053e80a9d539f54132d754343f8766900db06..c1f2d17ab4a60fc6c621e63098ba935c595e424e 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -70,7 +70,6 @@
 #include "ash/wm/system_modal_container_event_filter.h"
 #include "ash/wm/system_modal_container_layout_manager.h"
 #include "ash/wm/toplevel_window_event_handler.h"
-#include "ash/wm/user_activity_detector.h"
 #include "ash/wm/video_detector.h"
 #include "ash/wm/window_animations.h"
 #include "ash/wm/window_positioner.h"
@@ -106,6 +105,7 @@
 #include "ui/wm/core/focus_controller.h"
 #include "ui/wm/core/input_method_event_filter.h"
 #include "ui/wm/core/shadow_controller.h"
+#include "ui/wm/core/user_activity_detector.h"
 #include "ui/wm/core/visibility_controller.h"
 #include "ui/wm/core/window_modality_controller.h"
 
@@ -876,9 +876,9 @@ void Shell::Init() {
   AddPreTargetHandler(sticky_keys_controller_.get());
 #endif
 
-  // UserActivityDetector passes events to observers, so let them get
+  // wm::UserActivityDetector passes events to observers, so let them get
   // rewritten first.
-  user_activity_detector_.reset(new UserActivityDetector);
+  user_activity_detector_.reset(new ::wm::UserActivityDetector);
   AddPreTargetHandler(user_activity_detector_.get());
 
   overlay_filter_.reset(new internal::OverlayEventFilter);