Translate the overscroll elasticity layer by the overscroll amount

cc/input/top_controls_manager_unittest.cc

 // Copyright 2013 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 "cc/input/top_controls_manager.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "cc/input/top_controls_manager_client.h"
 #include "cc/layers/layer_impl.h"
@@ skipping 14 matching lines @@
                                float top_controls_show_threshold,
                                float top_controls_hide_threshold)
       : host_impl_(&proxy_, &shared_bitmap_manager_),
         redraw_needed_(false),
         update_draw_properties_needed_(false),
         top_controls_top_offset_(0.f),
         top_controls_height_(top_controls_height),
         top_controls_show_threshold_(top_controls_show_threshold),
         top_controls_hide_threshold_(top_controls_hide_threshold) {
     active_tree_ =
-        LayerTreeImpl::create(&host_impl_, new SyncedProperty<ScaleGroup>);
+        LayerTreeImpl::create(&host_impl_, new SyncedProperty<ScaleGroup>,
+                              new SyncedElasticOverscroll);
     root_scroll_layer_ = LayerImpl::Create(active_tree_.get(), 1);
   }
 
   ~MockTopControlsManagerClient() override {}
 
   void DidChangeTopControlsPosition() override {
     redraw_needed_ = true;
     update_draw_properties_needed_ = true;
   }
 
@@ skipping 404 matching lines @@
     time = base::TimeDelta::FromMicroseconds(100) + time;
     manager->Animate(time);
     EXPECT_GT(manager->ControlsTopOffset(), previous_offset);
     previous_offset = manager->ControlsTopOffset();
   }
   EXPECT_FALSE(manager->animation());
   EXPECT_EQ(0.f, manager->ControlsTopOffset());
 }
 }  // namespace
 }  // namespace cc