Update from https://crrev.com/307330

cc/trees/layer_tree_host.h

Index: cc/trees/layer_tree_host.h
diff --git a/cc/trees/layer_tree_host.h b/cc/trees/layer_tree_host.h
index 9d758c8cc37405f4cd30f1187a9cd6e6858609bc..75165ad08defd30d4bd68b6f4ccef2b806918a2e 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -223,6 +223,7 @@ class CC_EXPORT LayerTreeHost {
                                    float min_page_scale_factor,
                                    float max_page_scale_factor);
   float page_scale_factor() const { return page_scale_factor_; }
+  gfx::Vector2dF elastic_overscroll() const { return elastic_overscroll_; }
 
   SkColor background_color() const { return background_color_; }
   void set_background_color(SkColor color) { background_color_ = color; }
@@ -428,6 +429,7 @@ class CC_EXPORT LayerTreeHost {
   float page_scale_factor_;
   float min_page_scale_factor_;
   float max_page_scale_factor_;
+  gfx::Vector2dF elastic_overscroll_;
   bool has_gpu_rasterization_trigger_;
   bool content_is_suitable_for_gpu_rasterization_;
   bool gpu_rasterization_histogram_recorded_;