Revert of Move DefaultActivationClient to wm/core

ui/wm/test/wm_test_helper.h

Index: ui/wm/test/wm_test_helper.h
diff --git a/ui/wm/test/wm_test_helper.h b/ui/wm/test/wm_test_helper.h
index 52707a4e71c7d4487b64405b613e18434ccbde0f..1a3dd0964ac8fa492eb2ab41541275d40081bde9 100644
--- a/ui/wm/test/wm_test_helper.h
+++ b/ui/wm/test/wm_test_helper.h
@@ -14,6 +14,7 @@
 class Window;
 class WindowTreeHost;
 namespace client {
+class DefaultActivationClient;
 class DefaultCaptureClient;
 class FocusClient;
 }
@@ -50,6 +51,7 @@
   scoped_ptr<wm::CompoundEventFilter> root_window_event_filter_;
   scoped_ptr<aura::client::DefaultCaptureClient> capture_client_;
   scoped_ptr<wm::InputMethodEventFilter> input_method_filter_;
+  scoped_ptr<aura::client::DefaultActivationClient> activation_client_;
   scoped_ptr<aura::client::FocusClient> focus_client_;
 
   DISALLOW_COPY_AND_ASSIGN(WMTestHelper);