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

ui/app_list/presenter/app_list_presenter_impl.cc

Index: ui/app_list/presenter/app_list_presenter_impl.cc
diff --git a/ui/app_list/presenter/app_list_presenter_impl.cc b/ui/app_list/presenter/app_list_presenter_impl.cc
index c4ef309215f59c14134c09e053aa685c4a643e51..ea98f69ae9e8106e8d5149b47db788f32946d0f6 100644
--- a/ui/app_list/presenter/app_list_presenter_impl.cc
+++ b/ui/app_list/presenter/app_list_presenter_impl.cc
@@ -6,6 +6,7 @@
 
 #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"
@@ -34,7 +35,8 @@ inline ui::Layer* GetLayer(views::Widget* widget) {
 
 AppListPresenterImpl::AppListPresenterImpl(
     std::unique_ptr<AppListPresenterDelegateFactory> factory)
-    : factory_(std::move(factory)) {
+    : factory_(std::move(factory)),
+      is_fullscreen_app_list_enabled_(features::IsFullscreenAppListEnabled()) {
   DCHECK(factory_);
 }
 
@@ -272,7 +274,11 @@ void AppListPresenterImpl::TransitionChanged() {
 
   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();