Mark POWER key as system key so that it won't be passed to regular apps.

ui/wm/core/accelerator_delegate.h

Index: ui/wm/core/accelerator_delegate.h
diff --git a/ui/wm/core/accelerator_delegate.h b/ui/wm/core/accelerator_delegate.h
index 886d7dba44554b167ccc9e68df49f750bc02c5f2..a225a0e01b31d305fe72c0a2d5a8e9b4dc93f799 100644
--- a/ui/wm/core/accelerator_delegate.h
+++ b/ui/wm/core/accelerator_delegate.h
@@ -16,16 +16,9 @@ class AcceleratorDelegate {
  public:
   virtual ~AcceleratorDelegate() {}
 
-  // Type of keys that triggers accelerators.
-  enum KeyType {
-    KEY_TYPE_SYSTEM,
-    KEY_TYPE_OTHER,
-  };
-
   // Return true if the |accelerator| has been processed.
   virtual bool ProcessAccelerator(const ui::KeyEvent& event,
-                                  const ui::Accelerator& accelerator,
-                                  KeyType key_type) = 0;
+                                  const ui::Accelerator& accelerator) = 0;
 };
 
 }  // namespace wm