Plumb smooth scrolling in Chromium compositor

cc/trees/layer_tree_host_impl_unittest.cc

 // Copyright 2011 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/trees/layer_tree_host_impl.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/bind.h"
@@ skipping 4204 matching lines @@
         min_page_scale_factor_(-1.f),
         max_page_scale_factor_(-1.f),
         needs_animate_(false) {}
 
   ~TestScrollOffsetDelegate() override {}
 
   gfx::ScrollOffset GetTotalScrollOffset() override {
     return getter_return_value_;
   }
 
-  bool IsExternalScrollActive() const override { return false; }
-
   void SetNeedsAnimate(const AnimationCallback&) override {
     needs_animate_ = true;
   }
 
   void UpdateRootLayerState(const gfx::ScrollOffset& total_scroll_offset,
                             const gfx::ScrollOffset& max_scroll_offset,
                             const gfx::SizeF& scrollable_size,
                             float page_scale_factor,
                             float min_page_scale_factor,
                             float max_page_scale_factor) override {
@@ skipping 3996 matching lines @@
   // Hold an unowned pointer to the output surface to use for mock expectations.
   MockReclaimResourcesOutputSurface* mock_output_surface = output_surface.get();
 
   CreateHostImpl(DefaultSettings(), output_surface.Pass());
   EXPECT_CALL(*mock_output_surface, ForceReclaimResources()).Times(1);
   host_impl_->BeginCommit();
 }
 
 }  // namespace
 }  // namespace cc