Revert of Fix for menus blocking user activity detection (Retry 2).

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 6bf50fe06cfd5b3fc26c8eaef795f086e8e82a59..ee93a3421deaaf6943c754ee4addbe33574dd964 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -678,6 +678,7 @@
   RemovePreTargetHandler(speech_feedback_handler_.get());
   speech_feedback_handler_.reset();
 #endif
+  RemovePreTargetHandler(user_activity_detector_.get());
   RemovePreTargetHandler(overlay_filter_.get());
   RemovePreTargetHandler(input_method_filter_.get());
   RemovePreTargetHandler(accelerator_filter_.get());
@@ -921,6 +922,7 @@
   // ui::UserActivityDetector passes events to observers, so let them get
   // rewritten first.
   user_activity_detector_.reset(new ui::UserActivityDetector);
+  AddPreTargetHandler(user_activity_detector_.get());
 
   overlay_filter_.reset(new OverlayEventFilter);
   AddPreTargetHandler(overlay_filter_.get());