Introduce NON_ZERO_DURATION for animation unit tests

ui/wm/core/window_animations.cc

Index: ui/wm/core/window_animations.cc
diff --git a/ui/wm/core/window_animations.cc b/ui/wm/core/window_animations.cc
index 22fd43d387406c69d776c7c2344b5a7a895541ef..91f839dddde478429442c0f688b3597548f5e10c 100644
--- a/ui/wm/core/window_animations.cc
+++ b/ui/wm/core/window_animations.cc
@@ -26,6 +26,7 @@
 #include "ui/compositor/layer_animation_sequence.h"
 #include "ui/compositor/layer_animator.h"
 #include "ui/compositor/layer_tree_owner.h"
+#include "ui/compositor/scoped_animation_duration_scale_mode.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/gfx/animation/animation.h"
 #include "ui/gfx/interpolated_transform.h"
@@ -649,10 +650,23 @@ bool AnimateWindow(aura::Window* window, WindowAnimationType type) {
 }
 
 bool WindowAnimationsDisabled(aura::Window* window) {
-  return (!gfx::Animation::ShouldRenderRichAnimation() || (window &&
-          window->GetProperty(aura::client::kAnimationsDisabledKey)) ||
-      CommandLine::ForCurrentProcess()->HasSwitch(
-          switches::kWindowAnimationsDisabled));
+  // Individual windows can choose to skip animations.
+  if (window && window->GetProperty(aura::client::kAnimationsDisabledKey))
+    return true;
+
+  // Animations can be disabled globally for testing.
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kWindowAnimationsDisabled))
+    return true;
+
+  // Tests of animations themselves should still run even if the machine is
+  // being accessed via Remote Desktop.
+  if (ui::ScopedAnimationDurationScaleMode::duration_scale_mode() ==
+      ui::ScopedAnimationDurationScaleMode::TEST_DURATION)
+    return false;
+
+  // Let the user decide whether or not to play the animation.
+  return !gfx::Animation::ShouldRenderRichAnimation();
 }
 
 }  // namespace wm