cc :: Move tracking of layer_property_changed to main thread (2)

cc/trees/property_tree.cc

Index: cc/trees/property_tree.cc
diff --git a/cc/trees/property_tree.cc b/cc/trees/property_tree.cc
index ac8b60bb2b9184761af6a0461fbb4afffb5b3256..933b065302906b5b70709c56e2ca04c8a223929e 100644
--- a/cc/trees/property_tree.cc
+++ b/cc/trees/property_tree.cc
@@ -145,6 +145,7 @@ TransformNodeData::TransformNodeData()
       affected_by_outer_viewport_bounds_delta_x(false),
       affected_by_outer_viewport_bounds_delta_y(false),
       in_subtree_of_page_scale_layer(false),
+      transform_changed(false),
       post_local_scale_factor(1.0f),
       local_maximum_animation_target_scale(0.f),
       local_starting_animation_scale(0.f),
@@ -187,6 +188,7 @@ bool TransformNodeData::operator==(const TransformNodeData& other) const {
              other.affected_by_outer_viewport_bounds_delta_y &&
          in_subtree_of_page_scale_layer ==
              other.in_subtree_of_page_scale_layer &&
+         transform_changed == other.transform_changed &&
          post_local_scale_factor == other.post_local_scale_factor &&
          local_maximum_animation_target_scale ==
              other.local_maximum_animation_target_scale &&
@@ -270,6 +272,7 @@ void TransformNodeData::ToProtobuf(proto::TreeNode* proto) const {
       affected_by_outer_viewport_bounds_delta_y);
 
   data->set_in_subtree_of_page_scale_layer(in_subtree_of_page_scale_layer);
+  data->set_transform_changed(transform_changed);
   data->set_post_local_scale_factor(post_local_scale_factor);
   data->set_local_maximum_animation_target_scale(
       local_maximum_animation_target_scale);
@@ -335,6 +338,7 @@ void TransformNodeData::FromProtobuf(const proto::TreeNode& proto) {
       data.affected_by_outer_viewport_bounds_delta_y();
 
   in_subtree_of_page_scale_layer = data.in_subtree_of_page_scale_layer();
+  transform_changed = data.transform_changed();
   post_local_scale_factor = data.post_local_scale_factor();
   local_maximum_animation_target_scale =
       data.local_maximum_animation_target_scale();
@@ -594,10 +598,18 @@ bool TransformTree::NeedsSourceToParentUpdate(TransformNode* node) {
           node->parent_id != node->data.source_node_id);
 }
 
+void TransformTree::ResetChangeTracking() {
+  for (int id = 1; id < static_cast<int>(size()); ++id) {
+    TransformNode* node = Node(id);
+    node->data.transform_changed = false;
+  }
+}
+
 void TransformTree::UpdateTransforms(int id) {
   TransformNode* node = Node(id);
   TransformNode* parent_node = parent(node);
   TransformNode* target_node = Node(node->data.target_id);
+  TransformNode* source_node = Node(node->data.source_node_id);
   if (node->data.needs_local_transform_update ||
       NeedsSourceToParentUpdate(node))
     UpdateLocalTransform(node);
@@ -609,6 +621,7 @@ void TransformTree::UpdateTransforms(int id) {
   UpdateAnimationProperties(node, parent_node);
   UpdateSnapping(node);
   UpdateNodeAndAncestorsHaveIntegerTranslations(node, parent_node);
+  UpdateTransformChanged(node, parent_node, source_node);
 }
 
 bool TransformTree::IsDescendant(int desc_id, int source_id) const {
@@ -968,6 +981,19 @@ void TransformTree::UpdateSnapping(TransformNode* node) {
   node->data.scroll_snap = translation;
 }
 
+void TransformTree::UpdateTransformChanged(TransformNode* node,
+                                           TransformNode* parent_node,
+                                           TransformNode* source_node) {
+  if (parent_node && parent_node->data.transform_changed) {
+    node->data.transform_changed = true;
+    return;
+  }
+
+  if (source_node && source_node->id != parent_node->id &&
+      source_to_parent_updates_allowed_ && source_node->data.transform_changed)
+    node->data.transform_changed = true;
+}
+
 void TransformTree::SetDeviceTransform(const gfx::Transform& transform,
                                        gfx::PointF root_position) {
   gfx::Transform root_post_local = transform;