cc: Add a main thread LayerListIterator

cc/layers/layer_list_iterator_unittest.cc

Index: cc/layers/layer_list_iterator_unittest.cc
diff --git a/cc/layers/layer_list_iterator_unittest.cc b/cc/layers/layer_list_iterator_unittest.cc
index d0985096cb822d24e6b552c6234c8346d2ee7dbb..503c1e6d94a9dca3464a97413961ad44fb4c33f6 100644
--- a/cc/layers/layer_list_iterator_unittest.cc
+++ b/cc/layers/layer_list_iterator_unittest.cc
@@ -8,6 +8,7 @@
 
 #include "base/containers/adapters.h"
 #include "cc/test/fake_impl_task_runner_provider.h"
+#include "cc/test/fake_layer_tree_host.h"
 #include "cc/test/fake_layer_tree_host_impl.h"
 #include "cc/test/fake_output_surface.h"
 #include "cc/test/test_shared_bitmap_manager.h"
@@ -18,8 +19,184 @@
 namespace cc {
 namespace {
 
+// Layer version unit tests
+
 TEST(LayerListIteratorTest, VerifyTraversalOrder) {
   // Unfortunate preamble.
+  FakeLayerTreeHostClient client(FakeLayerTreeHostClient::DIRECT_3D);
+  TestTaskGraphRunner task_graph_runner;
+  std::unique_ptr<FakeLayerTreeHost> host_ptr =
+      FakeLayerTreeHost::Create(&client, &task_graph_runner);
+  FakeLayerTreeHost* host = host_ptr.get();
+
+  // This test constructs the following tree.
+  // 1
+  // +-2
+  // | +-3
+  // | +-4
+  // + 5
+  //   +-6
+  //   +-7
+  // We expect to visit all seven layers in that order.
+  scoped_refptr<Layer> layer1 = Layer::Create();
+  scoped_refptr<Layer> layer2 = Layer::Create();
+  scoped_refptr<Layer> layer3 = Layer::Create();
+  scoped_refptr<Layer> layer4 = Layer::Create();
+  scoped_refptr<Layer> layer5 = Layer::Create();
+  scoped_refptr<Layer> layer6 = Layer::Create();
+  scoped_refptr<Layer> layer7 = Layer::Create();
+
+  std::unordered_map<int, int> layer_id_to_order;
+  layer_id_to_order[layer1->id()] = 1;
+  layer_id_to_order[layer2->id()] = 2;
+  layer_id_to_order[layer3->id()] = 3;
+  layer_id_to_order[layer4->id()] = 4;
+  layer_id_to_order[layer5->id()] = 5;
+  layer_id_to_order[layer6->id()] = 6;
+  layer_id_to_order[layer7->id()] = 7;
+
+  layer2->AddChild(std::move(layer3));
+  layer2->AddChild(std::move(layer4));
+
+  layer5->AddChild(std::move(layer6));
+  layer5->AddChild(std::move(layer7));
+
+  layer1->AddChild(std::move(layer2));
+  layer1->AddChild(std::move(layer5));
+
+  host->SetRootLayer(std::move(layer1));
+
+  int i = 1;
+  for (auto* layer : *host) {
+    EXPECT_EQ(i++, layer_id_to_order[layer->id()]);
+  }
+  EXPECT_EQ(8, i);
+}
+
+TEST(LayerListIteratorTest, VerifySingleLayer) {
+  // Unfortunate preamble.
+  FakeLayerTreeHostClient client(FakeLayerTreeHostClient::DIRECT_3D);
+  TestTaskGraphRunner task_graph_runner;
+  std::unique_ptr<FakeLayerTreeHost> host_ptr =
+      FakeLayerTreeHost::Create(&client, &task_graph_runner);
+  FakeLayerTreeHost* host = host_ptr.get();
+
+  // This test constructs a tree consisting of a single layer.
+  scoped_refptr<Layer> layer1 = Layer::Create();
+  std::unordered_map<int, int> layer_id_to_order;
+  layer_id_to_order[layer1->id()] = 1;
+  host->SetRootLayer(std::move(layer1));
+
+  int i = 1;
+  for (auto* layer : *host) {
+    EXPECT_EQ(i++, layer_id_to_order[layer->id()]);
+  }
+  EXPECT_EQ(2, i);
+}
+
+TEST(LayerListIteratorTest, VerifyNullFirstLayer) {
+  // Ensures that if an iterator is constructed with a nullptr, that it can be
+  // iterated without issue and that it remains equal to any other
+  // null-initialized iterator.
+  LayerListIterator<Layer> it(nullptr);
+  LayerListIterator<Layer> end(nullptr);
+
+  EXPECT_EQ(it, end);
+  ++it;
+  EXPECT_EQ(it, end);
+}
+
+TEST(LayerListReverseIteratorTest, VerifyTraversalOrder) {
+  // Unfortunate preamble.
+  FakeLayerTreeHostClient client(FakeLayerTreeHostClient::DIRECT_3D);
+  TestTaskGraphRunner task_graph_runner;
+  std::unique_ptr<FakeLayerTreeHost> host_ptr =
+      FakeLayerTreeHost::Create(&client, &task_graph_runner);
+  FakeLayerTreeHost* host = host_ptr.get();
+
+  // This test constructs the following tree.
+  // 1
+  // +-2
+  // | +-3
+  // | +-4
+  // + 5
+  //   +-6
+  //   +-7
+  // We expect to visit all seven layers in reverse order.
+  scoped_refptr<Layer> layer1 = Layer::Create();
+  scoped_refptr<Layer> layer2 = Layer::Create();
+  scoped_refptr<Layer> layer3 = Layer::Create();
+  scoped_refptr<Layer> layer4 = Layer::Create();
+  scoped_refptr<Layer> layer5 = Layer::Create();
+  scoped_refptr<Layer> layer6 = Layer::Create();
+  scoped_refptr<Layer> layer7 = Layer::Create();
+
+  std::unordered_map<int, int> layer_id_to_order;
+  layer_id_to_order[layer1->id()] = 1;
+  layer_id_to_order[layer2->id()] = 2;
+  layer_id_to_order[layer3->id()] = 3;
+  layer_id_to_order[layer4->id()] = 4;
+  layer_id_to_order[layer5->id()] = 5;
+  layer_id_to_order[layer6->id()] = 6;
+  layer_id_to_order[layer7->id()] = 7;
+
+  layer2->AddChild(std::move(layer3));
+  layer2->AddChild(std::move(layer4));
+
+  layer5->AddChild(std::move(layer6));
+  layer5->AddChild(std::move(layer7));
+
+  layer1->AddChild(std::move(layer2));
+  layer1->AddChild(std::move(layer5));
+
+  host->SetRootLayer(std::move(layer1));
+
+  int i = 7;
+
+  for (auto* layer : base::Reversed(*host)) {
+    EXPECT_EQ(i--, layer_id_to_order[layer->id()]);
+  }
+
+  EXPECT_EQ(0, i);
+}
+
+TEST(LayerListReverseIteratorTest, VerifySingleLayer) {
+  // Unfortunate preamble.
+  FakeLayerTreeHostClient client(FakeLayerTreeHostClient::DIRECT_3D);
+  TestTaskGraphRunner task_graph_runner;
+  std::unique_ptr<FakeLayerTreeHost> host_ptr =
+      FakeLayerTreeHost::Create(&client, &task_graph_runner);
+  FakeLayerTreeHost* host = host_ptr.get();
+
+  // This test constructs a tree consisting of a single layer.
+  scoped_refptr<Layer> layer1 = Layer::Create();
+  std::unordered_map<int, int> layer_id_to_order;
+  layer_id_to_order[layer1->id()] = 1;
+  host->SetRootLayer(std::move(layer1));
+
+  int i = 1;
+  for (auto* layer : base::Reversed(*host)) {
+    EXPECT_EQ(i--, layer_id_to_order[layer->id()]);
+  }
+  EXPECT_EQ(0, i);
+}
+
+TEST(LayerListReverseIteratorTest, VerifyNullFirstLayer) {
+  // Ensures that if an iterator is constructed with a nullptr, that it can be
+  // iterated without issue and that it remains equal to any other
+  // null-initialized iterator.
+  LayerListReverseIterator<Layer> it(nullptr);
+  LayerListReverseIterator<Layer> end(nullptr);
+
+  EXPECT_EQ(it, end);
+  ++it;
+  EXPECT_EQ(it, end);
+}
+
+// LayerImpl version unit tests
+
+TEST(LayerListIteratorTest, VerifyTraversalOrderImpl) {
+  // Unfortunate preamble.
   FakeImplTaskRunnerProvider task_runner_provider;
   TestSharedBitmapManager shared_bitmap_manager;
   TestTaskGraphRunner task_graph_runner;
@@ -71,7 +248,7 @@ TEST(LayerListIteratorTest, VerifyTraversalOrder) {
   EXPECT_EQ(8, i);
 }
 
-TEST(LayerListIteratorTest, VerifySingleLayer) {
+TEST(LayerListIteratorTest, VerifySingleLayerImpl) {
   // Unfortunate preamble.
   FakeImplTaskRunnerProvider task_runner_provider;
   TestSharedBitmapManager shared_bitmap_manager;
@@ -94,19 +271,19 @@ TEST(LayerListIteratorTest, VerifySingleLayer) {
   EXPECT_EQ(2, i);
 }
 
-TEST(LayerListIteratorTest, VerifyNullFirstLayer) {
+TEST(LayerListIteratorTest, VerifyNullFirstLayerImpl) {
   // Ensures that if an iterator is constructed with a nullptr, that it can be
   // iterated without issue and that it remains equal to any other
   // null-initialized iterator.
-  LayerListIterator it(nullptr);
-  LayerListIterator end(nullptr);
+  LayerListIterator<LayerImpl> it(nullptr);
+  LayerListIterator<LayerImpl> end(nullptr);
 
   EXPECT_EQ(it, end);
   ++it;
   EXPECT_EQ(it, end);
 }
 
-TEST(LayerListReverseIteratorTest, VerifyTraversalOrder) {
+TEST(LayerListReverseIteratorTest, VerifyTraversalOrderImpl) {
   // Unfortunate preamble.
   FakeImplTaskRunnerProvider task_runner_provider;
   TestSharedBitmapManager shared_bitmap_manager;
@@ -161,7 +338,7 @@ TEST(LayerListReverseIteratorTest, VerifyTraversalOrder) {
   EXPECT_EQ(0, i);
 }
 
-TEST(LayerListReverseIteratorTest, VerifySingleLayer) {
+TEST(LayerListReverseIteratorTest, VerifySingleLayerImpl) {
   // Unfortunate preamble.
   FakeImplTaskRunnerProvider task_runner_provider;
   TestSharedBitmapManager shared_bitmap_manager;
@@ -184,12 +361,12 @@ TEST(LayerListReverseIteratorTest, VerifySingleLayer) {
   EXPECT_EQ(0, i);
 }
 
-TEST(LayerListReverseIteratorTest, VerifyNullFirstLayer) {
+TEST(LayerListReverseIteratorTest, VerifyNullFirstLayerImpl) {
   // Ensures that if an iterator is constructed with a nullptr, that it can be
   // iterated without issue and that it remains equal to any other
   // null-initialized iterator.
-  LayerListReverseIterator it(nullptr);
-  LayerListReverseIterator end(nullptr);
+  LayerListReverseIterator<LayerImpl> it(nullptr);
+  LayerListReverseIterator<LayerImpl> end(nullptr);
 
   EXPECT_EQ(it, end);
   ++it;