Disabled overscroll animation when the fullscreen app list feature is enabled.

ui/app_list/presenter/app_list_presenter_impl.cc

 // Copyright 2016 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 "ui/app_list/presenter/app_list_presenter_impl.h"
 
 #include "base/metrics/user_metrics.h"
 #include "ui/app_list/app_list_constants.h"
+#include "ui/app_list/app_list_features.h"
 #include "ui/app_list/app_list_switches.h"
 #include "ui/app_list/pagination_model.h"
 #include "ui/app_list/presenter/app_list_presenter_delegate_factory.h"
 #include "ui/app_list/views/app_list_view.h"
 #include "ui/aura/client/focus_client.h"
 #include "ui/aura/window.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/display/screen.h"
 #include "ui/views/widget/widget.h"
 
 namespace app_list {
 namespace {
 
 // Duration for show/hide animation in milliseconds.
 constexpr int kAnimationDurationMs = 200;
 
 // The maximum shift in pixels when over-scroll happens.
 constexpr int kMaxOverScrollShift = 48;
 
 inline ui::Layer* GetLayer(views::Widget* widget) {
   return widget->GetNativeView()->layer();
 }
 
 }  // namespace
 
 AppListPresenterImpl::AppListPresenterImpl(
     std::unique_ptr<AppListPresenterDelegateFactory> factory)
-    : factory_(std::move(factory)) {
+    : factory_(std::move(factory)),
+      is_fullscreen_app_list_enabled_(features::IsFullscreenAppListEnabled()) {
   DCHECK(factory_);
 }
 
 AppListPresenterImpl::~AppListPresenterImpl() {
   Dismiss();
   presenter_delegate_.reset();
   // Ensures app list view goes before the controller since pagination model
   // lives in the controller and app list view would access it on destruction.
   if (view_) {
     view_->GetAppsPaginationModel()->RemoveObserver(this);
@@ skipping 217 matching lines @@
 
 void AppListPresenterImpl::TransitionChanged() {
   // |view_| could be NULL when app list is closed with a running transition.
   if (!view_)
     return;
 
   PaginationModel* pagination_model = view_->GetAppsPaginationModel();
 
   const PaginationModel::Transition& transition =
       pagination_model->transition();
-  if (pagination_model->is_valid_page(transition.target_page))
+
+  // Disable overscroll animation when the fullscreen app list feature is
+  // enabled or when the transition is to a valid page.
+  if (is_fullscreen_app_list_enabled_ ||

[xiyuan, 2017/06/23 20:02:44]

nit: Move this to around line 272 and on its own "if" with the comment. The two
are not really the same thing so prefer to have separate "if"s.

[newcomer, 2017/06/26 16:13:58]

Done!

+      pagination_model->is_valid_page(transition.target_page))
     return;
 
   views::Widget* widget = view_->GetWidget();
   ui::LayerAnimator* widget_animator =
       widget->GetNativeView()->layer()->GetAnimator();
   if (!pagination_model->IsRevertingCurrentTransition()) {
     // Update cached |view_bounds_| if it is the first over-scroll move and
     // widget does not have running animations.
     if (!should_snap_back_ && !widget_animator->is_animating())
       view_bounds_ = widget->GetWindowBoundsInScreen();
@@ skipping 13 matching lines @@
   } else if (should_snap_back_) {
     should_snap_back_ = false;
     ui::ScopedLayerAnimationSettings animation(widget_animator);
     animation.SetTransitionDuration(
         base::TimeDelta::FromMilliseconds(kOverscrollPageTransitionDurationMs));
     widget->SetBounds(view_bounds_);
   }
 }
 
 }  // namespace app_list