Introduce NON_ZERO_DURATION for animation unit tests

content/browser/web_contents/aura/window_slider_unittest.cc

 // Copyright (c) 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 "content/browser/web_contents/aura/window_slider.h"
 
 #include "base/bind.h"
 #include "base/time/time.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/aura/test/aura_test_base.h"
@@ skipping 571 matching lines @@
 // that the second swipe occurs while the transition animation triggered by the
 // first swipe is in progress.
 // The second swipe is supposed to instantly complete the animation caused by
 // the first swipe, ask the delegate to create a new layer, and animate it.
 TEST_F(WindowSliderTest, SwipeDuringSwipeAnimation) {
   scoped_ptr<aura::Window> window(CreateNormalWindow(0, root_window(), NULL));
   window->SetBounds(gfx::Rect(0, 0, 400, 400));
   WindowSliderDelegateTest slider_delegate;
   new WindowSlider(&slider_delegate, root_window(), window.get());
 
-  ui::ScopedAnimationDurationScaleMode normal_duration_(
+  // This test uses explicit durations so needs a normal duration.
+  ui::ScopedAnimationDurationScaleMode normal_duration(
       ui::ScopedAnimationDurationScaleMode::NORMAL_DURATION);
   ui::LayerAnimator* animator = window->layer()->GetAnimator();
   animator->set_disable_timer_for_test(true);
   ui::LayerAnimatorTestController test_controller(animator);
 
   ui::test::EventGenerator generator(root_window());
 
   // Swipe forward so that |window|'s layer is the one animating.
   generator.GestureScrollSequence(
       gfx::Point(10, 10),
@@ skipping 35 matching lines @@
   animator->Step(start_time2 + duration);
   // The animation for the second slide should now be completed.
   EXPECT_TRUE(slider_delegate.slide_completed());
   slider_delegate.Reset();
 
   window.reset();
   EXPECT_TRUE(slider_delegate.slider_destroyed());
 }
 
 }  // namespace content