Pinch/Zoom Infrastructure & Plumbing CL

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 90c8c258e8b01a84888a61712f934654934c4979..75cddcc6700a6cdb6fbfa9a48b4d57a9e6855ed1 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -231,6 +231,12 @@ class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
       scoped_refptr<Layer> page_scale_layer,
       scoped_refptr<Layer> inner_viewport_scroll_layer,
       scoped_refptr<Layer> outer_viewport_scroll_layer);
+  Layer* inner_viewport_scroll_layer() const {
+    return inner_viewport_scroll_layer_.get();
+  }
+  Layer* outer_viewport_scroll_layer() const {
+    return outer_viewport_scroll_layer_.get();
+  }
 
   const LayerTreeSettings& settings() const { return settings_; }
 
@@ -271,6 +277,8 @@ class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
                                base::TimeDelta duration);
 
   void ApplyScrollAndScale(const ScrollAndScaleSet& info);
+  gfx::Vector2d DistributeScrollOffsetToViewports(const gfx::Vector2d& offset,
+                                                  Layer* layer);
 
   void SetImplTransform(const gfx::Transform& transform);
   void SetLatencyInfo(const ui::LatencyInfo& latency_info);