Introduce Property Trees

cc/layers/layer.cc

Index: cc/layers/layer.cc
diff --git a/cc/layers/layer.cc b/cc/layers/layer.cc
index 08f39b9a21d6d67805fef6150237b57f3c51f810..7cf0e0fb915611828513d155de71350f70b70e3f 100644
--- a/cc/layers/layer.cc
+++ b/cc/layers/layer.cc
@@ -49,6 +49,9 @@ Layer::Layer()
       layer_tree_host_(nullptr),
       scroll_clip_layer_id_(INVALID_ID),
       num_descendants_that_draw_content_(0),
+      transform_tree_index_(-1),
+      opacity_tree_index_(-1),
+      clip_tree_index_(-1),
       should_scroll_on_main_thread_(false),
       have_wheel_event_handlers_(false),
       have_scroll_event_handlers_(false),
@@ -1233,6 +1236,10 @@ void Layer::AddDrawableDescendants(int num) {
     parent()->AddDrawableDescendants(num);
 }
 
+bool Layer::NeedsVisibleRectUpdated() const {
+  return DrawsContent();
+}
+
 void Layer::RunMicroBenchmark(MicroBenchmark* benchmark) {
   benchmark->RunOnLayer(this);
 }
@@ -1241,4 +1248,32 @@ bool Layer::HasDelegatedContent() const {
   return false;
 }
 
+gfx::Transform Layer::debug_screen_space_transform(
+    const TransformTree& tree) const {
+  gfx::Transform xform(1, 0, 0, 1, offset_to_transform_parent().x(),
+                       offset_to_transform_parent().y());
+  if (transform_tree_index() >= 0) {
+    gfx::Transform ssxform = tree.Node(transform_tree_index())->data.to_screen;
+    xform.ConcatTransform(ssxform);
+  }
+  xform.Scale(1.0 / contents_scale_x(), 1.0 / contents_scale_y());
+  return xform;
+}
+
+gfx::Transform Layer::debug_draw_transform(const TransformTree& tree) const {
+  if (!has_render_target())
+    return debug_screen_space_transform(tree);
+
+  gfx::Transform xform(1, 0, 0, 1, offset_to_transform_parent().x(),
+                       offset_to_transform_parent().y());
+  if (transform_tree_index() >= 0) {
+    gfx::Transform ssxform;
+    ComputeTransform(tree, transform_tree_index(),
+                     render_target()->transform_tree_index(), &ssxform);
+    xform.ConcatTransform(ssxform);
+  }
+  xform.Scale(1.0 / contents_scale_x(), 1.0 / contents_scale_y());
+  return xform;
+}
+
 }  // namespace cc