Fix memory leak in sticky keys unit test.

ash/wm/sticky_keys_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/wm/sticky_keys.h"
 
 #include <X11/Xlib.h>
 #undef None
 #undef Bool
 
@@ skipping 81 matching lines @@
     dispatcher.set_target(target_.get());
     return event;
   }
 
   ui::MouseEvent* GenerateMouseEvent(bool is_button_press) {
     XEvent* xev = new XEvent();
     ui::InitXButtonEventForTesting(
         is_button_press ? ui::ET_MOUSE_PRESSED : ui::ET_MOUSE_RELEASED,
         0,
         xev);
+    xevs_.push_back(xev);
     ui::MouseEvent* event = new ui::MouseEvent(xev);
     ui::Event::DispatcherApi dispatcher(event);
     dispatcher.set_target(target_.get());
     return event;
   }
 
   ui::MouseWheelEvent* GenerateMouseWheelEvent(int wheel_delta) {
     EXPECT_FALSE(wheel_delta == 0);
     XEvent* xev = new XEvent();
     ui::InitXMouseWheelEventForTesting(wheel_delta, 0, xev);
+    xevs_.push_back(xev);
     ui::MouseWheelEvent* event = new ui::MouseWheelEvent(xev);
     ui::Event::DispatcherApi dispatcher(event);
     dispatcher.set_target(target_.get());
     return event;
   }
 
  private:
   scoped_ptr<StubEventTarget> target_;
   ScopedVector<XEvent> xevs_;
 };
@@ skipping 266 matching lines @@
   sticky_key.HandleMouseEvent(ev.get());
   EXPECT_TRUE(ev->flags() & ui::EF_CONTROL_DOWN);
   kev.reset(GenerateKey(true, ui::VKEY_N));
   sticky_key.HandleKeyEvent(kev.get());
   kev.reset(GenerateKey(false, ui::VKEY_N));
   sticky_key.HandleKeyEvent(kev.get());
   EXPECT_EQ(StickyKeysHandler::LOCKED, sticky_key.current_state());
 }
 
 }  // namespace ash