Register a separate default ui::EventTarget for Aura (Ash) to ensure that it does not interfere wit…

ash/shell.cc

Index: ash/shell.cc
===================================================================
--- ash/shell.cc	(revision 163961)
+++ ash/shell.cc	(working copy)
@@ -509,12 +509,20 @@
   env_filter_->set_cursor_hidden_by_filter(true);
 }
 
+bool Shell::CanAcceptEvents() {
+  return true;
+}
+
+ui::EventTarget* Shell::GetParentTarget() {
+  return NULL;
+}
+
 void Shell::AddEnvEventFilter(aura::EventFilter* filter) {
-  aura::Env::GetInstance()->AddPreTargetHandler(filter);
+  AddPreTargetHandler(filter);
 }
 
 void Shell::RemoveEnvEventFilter(aura::EventFilter* filter) {
-  aura::Env::GetInstance()->RemovePreTargetHandler(filter);
+  RemovePreTargetHandler(filter);
 }
 
 void Shell::ShowContextMenu(const gfx::Point& location_in_screen) {