Move DefaultActivationClient to wm/core

ui/aura/test/aura_test_helper.cc

Index: ui/aura/test/aura_test_helper.cc
diff --git a/ui/aura/test/aura_test_helper.cc b/ui/aura/test/aura_test_helper.cc
index b300dcfce9d3d3aa48160dcad24b8c6847f76e92..34183db5921f946f8e0aa3d31acfb74e57714cdd 100644
--- a/ui/aura/test/aura_test_helper.cc
+++ b/ui/aura/test/aura_test_helper.cc
@@ -7,7 +7,6 @@
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "ui/aura/client/aura_constants.h"
-#include "ui/aura/client/default_activation_client.h"
 #include "ui/aura/client/default_capture_client.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/env.h"
@@ -71,8 +70,6 @@ void AuraTestHelper::SetUp() {
   focus_client_.reset(new TestFocusClient);
   client::SetFocusClient(root_window(), focus_client_.get());
   stacking_client_.reset(new TestWindowTreeClient(root_window()));
-  activation_client_.reset(
-      new client::DefaultActivationClient(root_window()));
   capture_client_.reset(new client::DefaultCaptureClient(root_window()));
   test_input_method_.reset(new ui::DummyInputMethod);
   root_window()->SetProperty(
@@ -88,7 +85,6 @@ void AuraTestHelper::TearDown() {
   teardown_called_ = true;
   test_input_method_.reset();
   stacking_client_.reset();
-  activation_client_.reset();
   capture_client_.reset();
   focus_client_.reset();
   client::SetFocusClient(root_window(), NULL);