cc: Remove usage of ComputeVisibleRects on main thread

cc/debug/invalidation_benchmark.cc

Index: cc/debug/invalidation_benchmark.cc
diff --git a/cc/debug/invalidation_benchmark.cc b/cc/debug/invalidation_benchmark.cc
index 681e29ef7cced1b62c1f9303d22c0c26df7494af..458ccf687006dab3fd1608b94642d58429010cc9 100644
--- a/cc/debug/invalidation_benchmark.cc
+++ b/cc/debug/invalidation_benchmark.cc
@@ -70,11 +70,18 @@ void InvalidationBenchmark::DidUpdateLayers(LayerTreeHost* host) {
 
 void InvalidationBenchmark::RunOnLayer(PictureLayer* layer) {
   PropertyTrees* property_trees = layer->layer_tree_host()->property_trees();
-  LayerList update_list;
-  update_list.push_back(layer);
-  draw_property_utils::ComputeVisibleRectsForTesting(
-      property_trees, property_trees->non_root_surfaces_enabled, &update_list);
-  gfx::Rect visible_layer_rect = layer->visible_layer_rect_for_testing();
+  const TransformTree& transform_tree = property_trees->transform_tree;
+  int index = layer->transform_tree_index();
+  layer->layer_tree_host()->BuildPropertyTreesForTesting();
+  gfx::Point position =
+      gfx::Point(layer->position().x(), layer->position().y());
+  gfx::Rect layer_rect = gfx::Rect(position, layer->bounds());

[ajuma, 2016/08/09 20:44:01]

The screen space transform already accounts for the layer's position, so we
shouldn't need to use |position| here.

+  gfx::Rect screen_space_rect = MathUtil::MapEnclosingClippedRect(
+      transform_tree.ToScreen(index), layer_rect);

[ajuma, 2016/08/09 20:44:01]

This should use Layer::screen_space_transform (since transform_tree.ToScreen
doesn't account for the layer's offset to its transform parent).

+  screen_space_rect.Intersect(
+      gfx::Rect(layer->layer_tree_host()->device_viewport_size()));

[ajuma, 2016/08/09 20:44:01]

I wonder if it would be simpler to just start with the viewport, project that
into layer space, and intersect with the layer's bounds.

+  gfx::Rect visible_layer_rect = MathUtil::ProjectEnclosingClippedRect(
+      transform_tree.FromScreen(index), screen_space_rect);

[ajuma, 2016/08/09 20:44:01]

And this needs to use the inverse of Layer::screen_space_transform.

   switch (mode_) {
     case FIXED_SIZE: {
       // Invalidation with a random position and fixed size.