ui: Add debug flag for slowing down all UI animations.

ui/compositor/compositor.h

 // Copyright (c) 2012 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.
 
 #ifndef UI_COMPOSITOR_COMPOSITOR_H_
 #define UI_COMPOSITOR_COMPOSITOR_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 47 matching lines @@
 class GpuMemoryBufferManager;
 }
 
 namespace ui {
 
 class Compositor;
 class CompositorVSyncManager;
 class LatencyInfo;
 class Layer;
 class Reflector;
+class ScopedAnimationDurationScaleMode;
 
 #if defined(USE_AURA)
 class Window;
 #endif
 
 const int kCompositorLockTimeoutMs = 67;
 
 class COMPOSITOR_EXPORT ContextFactoryObserver {
  public:
   virtual ~ContextFactoryObserver() {}
@@ skipping 351 matching lines @@
 
   // The device scale factor of the monitor that this compositor is compositing
   // layers on.
   float device_scale_factor_;
 
   bool locks_will_time_out_;
   CompositorLock* compositor_lock_;
 
   LayerAnimatorCollection layer_animator_collection_;
   scoped_refptr<cc::AnimationTimeline> animation_timeline_;
+  std::unique_ptr<ScopedAnimationDurationScaleMode> slow_animations_;
 
   gfx::ColorSpace color_space_;
 
   base::WeakPtrFactory<Compositor> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Compositor);
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_COMPOSITOR_H_