Build mapping from element id to transform/effect nodes.

cc/trees/layer_tree_host_unittest.cc

Index: cc/trees/layer_tree_host_unittest.cc
diff --git a/cc/trees/layer_tree_host_unittest.cc b/cc/trees/layer_tree_host_unittest.cc
index 5e58148f9db03b81fc5af4b916472398a081e627..68813d7c95ee1d05d6d70062cf84492916f1c336 100644
--- a/cc/trees/layer_tree_host_unittest.cc
+++ b/cc/trees/layer_tree_host_unittest.cc
@@ -30,7 +30,6 @@
 #include "cc/output/copy_output_result.h"
 #include "cc/output/output_surface.h"
 #include "cc/output/swap_promise.h"
-#include "cc/playback/display_item_list_settings.h"
 #include "cc/quads/draw_quad.h"
 #include "cc/quads/render_pass_draw_quad.h"
 #include "cc/quads/tile_draw_quad.h"
@@ -918,6 +917,87 @@ class LayerTreeHostTestPushNodeOwnerToNodeIdMap : public LayerTreeHostTest {
 // engine will never build PropertyTrees in LTH remote. See crbug.com/655795.
 SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestPushNodeOwnerToNodeIdMap);
 
+class LayerTreeHostTestPushElementIdToNodeIdMap : public LayerTreeHostTest {
+ protected:
+  void SetupTree() override {
+    root_ = Layer::Create();
+    child_ = Layer::Create();
+    child_->SetElementId(kTestElementId);
+    root_->AddChild(child_);
+    layer_tree()->SetRootLayer(root_);
+    LayerTreeHostTest::SetupTree();
+  }
+
+  void BeginTest() override { PostSetNeedsCommitToMainThread(); }
+
+  void DidCommit() override {
+    switch (layer_tree_host()->SourceFrameNumber()) {
+      case 1:
+        child_->SetForceRenderSurfaceForTesting(true);
+        break;
+      case 2:
+        child_->SetForceRenderSurfaceForTesting(false);
+        break;
+    }
+  }
+
+  void CommitCompleteOnThread(LayerTreeHostImpl* impl) override {
+    PropertyTrees* property_trees = impl->sync_tree()->property_trees();
+    auto root_element_id_to_transform_node_index =

[ajuma, 2017/01/10 00:02:36]

int child_transform_node_index

[wkorman, 2017/01/10 00:13:09]

Moved inline to the one case statement where it's now used.

+        property_trees->element_id_to_transform_node_index[kTestElementId];
+    auto root_element_id_to_effect_node_index =

[ajuma, 2017/01/10 00:02:36]

int child_effect_node_index

[wkorman, 2017/01/10 00:13:09]

Moved inline to the one case statement where it's now used.

+        property_trees->element_id_to_effect_node_index[kTestElementId];
+
+    LayerImpl* child_impl_ = impl->active_tree()->LayerById(child_->id());
+    switch (impl->sync_tree()->source_frame_number()) {
+      case 0:
+        EXPECT_EQ(2U, child_impl_->layer_tree_impl()
+                          ->property_trees()
+                          ->transform_tree.size());
+        EXPECT_EQ(2U, child_impl_->layer_tree_impl()
+                          ->property_trees()
+                          ->effect_tree.size());
+        EXPECT_EQ(0, root_element_id_to_transform_node_index);
+        EXPECT_EQ(0, root_element_id_to_effect_node_index);

[ajuma, 2017/01/10 00:02:36]

These 0s are because kTestElementId isn't present in the map, right? It'd be
good to check for that explicitly (to distinguish from 0 being the actual
index).

[wkorman, 2017/01/10 00:13:09]

Good point, revised here and below to find() == end() instead.

+        break;
+      case 1:
+        EXPECT_EQ(3U, child_impl_->layer_tree_impl()

[wkorman, 2017/01/09 21:41:55]

We don't currently set the element id on the transform/effect nodes (though
maybe we'll find we want to do that later; scroll node does have it, for
example) so there wasn't much I saw to check in the test other than that the new
nodes exist, and go away when expected. You had mentioned explicitly to check
the tree structure, so if there's more I should do here let me know.

+                          ->property_trees()
+                          ->transform_tree.size());
+        EXPECT_EQ(3U, child_impl_->layer_tree_impl()
+                          ->property_trees()
+                          ->effect_tree.size());
+        EXPECT_EQ(2, root_element_id_to_transform_node_index);
+        EXPECT_EQ(2, root_element_id_to_effect_node_index);
+        break;
+      case 2:
+        EXPECT_EQ(2U, child_impl_->layer_tree_impl()
+                          ->property_trees()
+                          ->transform_tree.size());
+        EXPECT_EQ(2U, child_impl_->layer_tree_impl()
+                          ->property_trees()
+                          ->effect_tree.size());
+        EXPECT_EQ(0, root_element_id_to_transform_node_index);
+        EXPECT_EQ(0, root_element_id_to_effect_node_index);

[ajuma, 2017/01/10 00:02:36]

Same comment about checking that kTestElementId isn't present in the maps.

[wkorman, 2017/01/10 00:13:09]

Done.

+        break;
+    }
+    EndTest();
+  }
+
+  void AfterTest() override {}
+
+ private:
+  const ElementId kTestElementId = ElementId(42, 8118);
+
+  scoped_refptr<Layer> root_;
+  scoped_refptr<Layer> child_;
+};
+
+// Validates that, for a layer with a compositor element id set on it, mappings
+// from compositor element id to transform/effect node indexes are created as
+// part of building a layer's property tree and are present on the impl thread.
+SINGLE_AND_MULTI_THREAD_TEST_F(LayerTreeHostTestPushElementIdToNodeIdMap);
+
 class LayerTreeHostTestSurfaceDamage : public LayerTreeHostTest {
  protected:
   void SetupTree() override {