cc: Compute draw transforms dynamically.

cc/trees/property_tree.h

Index: cc/trees/property_tree.h
diff --git a/cc/trees/property_tree.h b/cc/trees/property_tree.h
index 4f3a501cc20bf46b5538ee84d3875b78a3438c86..59c15eefc88e88f8e03479d8e52cdee92bb6a92a 100644
--- a/cc/trees/property_tree.h
+++ b/cc/trees/property_tree.h
@@ -7,6 +7,7 @@
 
 #include <stddef.h>
 
+#include <map>
 #include <memory>
 #include <unordered_map>
 #include <vector>
@@ -142,19 +143,6 @@ class CC_EXPORT TransformTree final : public PropertyTree<TransformNode> {
 
   void clear();
 
-  // Computes the change of basis transform from node |source_id| to |dest_id|.
-  // The function returns false iff the inverse of a singular transform was
-  // used (and the result should, therefore, not be trusted). Transforms may
-  // be computed between any pair of nodes that have an ancestor/descendant
-  // relationship. Transforms between other pairs of nodes may only be computed
-  // if the following condition holds: let id1 the larger id and let id2 be the
-  // other id; then the nearest ancestor of node id1 whose id is smaller than
-  // id2 is the lowest common ancestor of the pair of nodes, and the transform
-  // from this lowest common ancestor to node id2 is only a 2d translation.
-  bool ComputeTransform(int source_id,
-                        int dest_id,
-                        gfx::Transform* transform) const;
-
   void OnTransformAnimated(const gfx::Transform& transform,
                            int id,
                            LayerTreeImpl* layer_tree_impl);
@@ -232,12 +220,7 @@ class CC_EXPORT TransformTree final : public PropertyTree<TransformNode> {
   }
 
   const gfx::Transform& FromTarget(int node_id, int effect) const;
-  void SetFromTarget(int node_id, const gfx::Transform& transform);
-
-  // TODO(sunxd): Remove target space transforms in cached data when we
-  // completely implement computing draw transforms on demand.
   const gfx::Transform& ToTarget(int node_id, int effect_id) const;
-  void SetToTarget(int node_id, const gfx::Transform& transform);
 
   const gfx::Transform& FromScreen(int node_id) const;
   void SetFromScreen(int node_id, const gfx::Transform& transform);
@@ -259,19 +242,6 @@ class CC_EXPORT TransformTree final : public PropertyTree<TransformNode> {
   void FromProtobuf(const proto::PropertyTree& proto,
                     std::unordered_map<int, int>* node_id_to_index_map);
 
-  // Computes the combined transform between |source_id| and |dest_id|. These
-  // two nodes must be on the same ancestor chain.
-  void CombineTransformsBetween(int source_id,
-                                int dest_id,
-                                gfx::Transform* transform) const;
-
-  // Computes the combined inverse transform between |source_id| and |dest_id|
-  // and returns false if the inverse of a singular transform was used. These
-  // two nodes must be on the same ancestor chain.
-  bool CombineInversesBetween(int source_id,
-                              int dest_id,
-                              gfx::Transform* transform) const;
-
  private:
   // Returns true iff the node at |desc_id| is a descendant of the node at
   // |anc_id|.
@@ -521,8 +491,7 @@ struct DrawTransformData {
 struct PropertyTreesCachedData {
   int property_tree_update_number;
   std::vector<AnimationScaleData> animation_scales;
-  mutable std::vector<std::unordered_map<int, DrawTransformData>>
-      draw_transforms;
+  mutable std::vector<std::map<int, DrawTransformData>> draw_transforms;

[ajuma, 2016/09/07 14:51:23]

As discussed offline, please compare the performance of using unordered_map vs
map here on the telemetry cluster.

[sunxd, 2016/09/07 15:20:02]

Acknowledged.

 
   PropertyTreesCachedData();
   ~PropertyTreesCachedData();
@@ -567,7 +536,6 @@ class CC_EXPORT PropertyTrees final {
   int sequence_number;
   bool is_main_thread;
   bool is_active;
-  bool verify_transform_tree_calculations;
 
   void clear();