Implemented swipe to close in overview mode.

ash/wm/overview/scoped_overview_animation_settings.cc

Index: ash/wm/overview/scoped_overview_animation_settings.cc
diff --git a/ash/wm/overview/scoped_overview_animation_settings.cc b/ash/wm/overview/scoped_overview_animation_settings.cc
index e0cf9776e9cbe09039d7aafdd716cc5d22ce2735..df3af61f2633ebb5f80fa841aec1a411a997c702 100644
--- a/ash/wm/overview/scoped_overview_animation_settings.cc
+++ b/ash/wm/overview/scoped_overview_animation_settings.cc
@@ -23,6 +23,7 @@ const int kFadeInMilliseconds = 80;
 base::TimeDelta GetAnimationDuration(OverviewAnimationType animation_type) {
   switch (animation_type) {
     case OVERVIEW_ANIMATION_NONE:
+    case SELECTOR_ITEM_SCROLL:
       return base::TimeDelta();
     case OVERVIEW_ANIMATION_ENTER_OVERVIEW_MODE_FADE_IN:
       return base::TimeDelta::FromMilliseconds(kFadeInMilliseconds);
@@ -30,6 +31,8 @@ base::TimeDelta GetAnimationDuration(OverviewAnimationType animation_type) {
     case OVERVIEW_ANIMATION_RESTORE_WINDOW:
     case OVERVIEW_ANIMATION_HIDE_WINDOW:
       return base::TimeDelta::FromMilliseconds(kTransitionMilliseconds);
+    case SELECTOR_ITEM_SCROLL_CANCEL:
+      return base::TimeDelta::FromMilliseconds(kTransitionMilliseconds);
   }
   NOTREACHED();
   return base::TimeDelta();
@@ -44,6 +47,7 @@ ScopedOverviewAnimationSettings::ScopedOverviewAnimationSettings(
 
   switch (animation_type) {
     case OVERVIEW_ANIMATION_NONE:
+    case SELECTOR_ITEM_SCROLL:
       animation_settings_.SetPreemptionStrategy(
           ui::LayerAnimator::REPLACE_QUEUED_ANIMATIONS);
       break;
@@ -65,6 +69,11 @@ ScopedOverviewAnimationSettings::ScopedOverviewAnimationSettings(
       animation_settings_.SetPreemptionStrategy(
           ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
       break;
+    case SELECTOR_ITEM_SCROLL_CANCEL:
+      animation_settings_.SetPreemptionStrategy(
+          ui::LayerAnimator::IMMEDIATELY_ANIMATE_TO_NEW_TARGET);
+      animation_settings_.SetTweenType(gfx::Tween::EASE_IN_OUT);
+      break;
   }
   animation_settings_.SetTransitionDuration(
       GetAnimationDuration(animation_type));