cc: Replace LayerIterator with iterator that walks layer list and effect tree

cc/BUILD.gn

Index: cc/BUILD.gn
diff --git a/cc/BUILD.gn b/cc/BUILD.gn
index 76923ac76697d977cc3217c2c4938fa286dd250b..6ffaeddd3670dbde3cb77e8515ba87106109ef93 100644
--- a/cc/BUILD.gn
+++ b/cc/BUILD.gn
@@ -52,6 +52,8 @@ cc_component("cc") {
     "layers/content_layer_client.h",
     "layers/draw_properties.cc",
     "layers/draw_properties.h",
+    "layers/effect_tree_layer_list_iterator.cc",
+    "layers/effect_tree_layer_list_iterator.h",
     "layers/heads_up_display_layer.cc",
     "layers/heads_up_display_layer.h",
     "layers/heads_up_display_layer_impl.cc",
@@ -64,7 +66,6 @@ cc_component("cc") {
     "layers/layer_impl.h",
     "layers/layer_impl_test_properties.cc",
     "layers/layer_impl_test_properties.h",
-    "layers/layer_iterator.h",
     "layers/layer_list_iterator.cc",
     "layers/layer_list_iterator.h",
     "layers/layer_position_constraint.cc",
@@ -716,10 +717,10 @@ cc_test("cc_unittests") {
     "input/single_scrollbar_animation_controller_thinning_unittest.cc",
     "ipc/cc_param_traits_unittest.cc",
     "ipc/struct_traits_unittest.cc",
+    "layers/effect_tree_layer_list_iterator_unittest.cc",
     "layers/heads_up_display_layer_impl_unittest.cc",
     "layers/heads_up_display_unittest.cc",
     "layers/layer_impl_unittest.cc",
-    "layers/layer_iterator_unittest.cc",
     "layers/layer_list_iterator_unittest.cc",
     "layers/layer_position_constraint_unittest.cc",
     "layers/layer_unittest.cc",