cc/blimp: Set up the framework for state serialization.

cc/blimp/compositor_state_deserializer_unittest.cc

Index: cc/blimp/compositor_state_deserializer_unittest.cc
diff --git a/cc/blimp/compositor_state_deserializer_unittest.cc b/cc/blimp/compositor_state_deserializer_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..3d86f3193b07b9f8da06046b56fee4863587afa7
--- /dev/null
+++ b/cc/blimp/compositor_state_deserializer_unittest.cc
@@ -0,0 +1,421 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "compositor_state_deserializer.h"
+
+#include "base/run_loop.h"
+#include "cc/animation/animation_host.h"
+#include "cc/blimp/compositor_proto_state.h"
+#include "cc/blimp/compositor_state_deserializer_client.h"
+#include "cc/blimp/layer_tree_host_remote.h"
+#include "cc/proto/compositor_message.pb.h"
+#include "cc/test/fake_layer_tree_host.h"
+#include "cc/test/fake_layer_tree_host_client.h"
+#include "cc/test/fake_remote_compositor_bridge.h"
+#include "cc/test/remote_client_layer_factory.h"
+#include "cc/test/stub_layer_tree_host_client.h"
+#include "cc/test/test_task_graph_runner.h"
+#include "cc/trees/layer_tree_host_common.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace cc {
+namespace {
+
+#define EXPECT_LAYERS_EQ(engine_layer_id, client_layer)                     \
+  EXPECT_EQ(                                                                \
+      compositor_state_deserializer_->GetLayerForEngineId(engine_layer_id), \
+      client_layer);
+
+class RemoteCompositorBridgeForTest : public FakeRemoteCompositorBridge {
+ public:
+  using ProtoFrameCallback = base::Callback<void(
+      std::unique_ptr<CompositorProtoState> compositor_proto_state)>;
+
+  RemoteCompositorBridgeForTest(
+      scoped_refptr<base::SingleThreadTaskRunner> main_task_runner,
+      ProtoFrameCallback proto_frame_callback)
+      : FakeRemoteCompositorBridge(main_task_runner),
+        proto_frame_callback_(proto_frame_callback) {}
+
+  ~RemoteCompositorBridgeForTest() override = default;
+
+  void ProcessCompositorStateUpdate(
+      std::unique_ptr<CompositorProtoState> compositor_proto_state) override {
+    proto_frame_callback_.Run(std::move(compositor_proto_state));
+  }
+
+ private:
+  ProtoFrameCallback proto_frame_callback_;
+};
+
+class CompositorStateDeserializerTest
+    : public testing::Test,
+      public CompositorStateDeserializerClient {
+ public:
+  void SetUp() override {
+    scoped_refptr<base::SingleThreadTaskRunner> main_task_runner =
+        base::ThreadTaskRunnerHandle::Get();
+
+    // Engine side setup.
+    LayerTreeHostRemote::InitParams params;
+    params.client = &layer_tree_host_client_remote_;
+    params.main_task_runner = main_task_runner;
+    params.animation_host = AnimationHost::CreateMainInstance();
+    params.remote_compositor_bridge =
+        base::MakeUnique<RemoteCompositorBridgeForTest>(
+            main_task_runner,
+            base::Bind(
+                &CompositorStateDeserializerTest::ProcessCompositorStateUpdate,
+                base::Unretained(this)));
+    LayerTreeSettings settings;
+    params.settings = &settings;
+
+    layer_tree_host_remote_ = base::MakeUnique<LayerTreeHostRemote>(&params);
+
+    // Client side setup.
+    layer_tree_host_in_process_ = FakeLayerTreeHost::Create(
+        &layer_tree_host_client_client_, &task_graph_runner_);
+    compositor_state_deserializer_ =
+        base::MakeUnique<CompositorStateDeserializer>(
+            layer_tree_host_in_process_.get(),
+            base::Bind(&CompositorStateDeserializerTest::LayerScrolled,
+                       base::Unretained(this)),
+            this);
+  }
+
+  void TearDown() override {
+    layer_tree_host_remote_ = nullptr;
+    compositor_state_deserializer_ = nullptr;
+    layer_tree_host_in_process_ = nullptr;
+  }
+
+  void ProcessCompositorStateUpdate(
+      std::unique_ptr<CompositorProtoState> compositor_proto_state) {
+    // Immediately deserialize the state update.
+    compositor_state_deserializer_->DeserializeCompositorUpdate(
+        compositor_proto_state->compositor_message->layer_tree_host());
+  }
+
+  // CompositorStateDeserializer implementation.
+  bool ShouldRetainClientScroll(int engine_layer_id,
+                                const gfx::ScrollOffset& new_offset) override {
+    return should_retain_client_scroll_;
+  }
+  bool ShouldRetainClientPageScale(float new_page_scale) override {
+    return should_retain_client_scale_;
+  }
+
+  void LayerScrolled(int engine_layer_id) {}
+
+  void VerifyTreesAreIdentical() {
+    LayerTree* engine_layer_tree = layer_tree_host_remote_->GetLayerTree();
+    LayerTree* client_layer_tree = layer_tree_host_in_process_->GetLayerTree();
+
+    if (engine_layer_tree->root_layer()) {
+      LayerTreeHostCommon::CallFunctionForEveryLayer(
+          engine_layer_tree, [this](Layer* engine_layer) {
+            VerifyLayersAreIdentical(
+                engine_layer,
+                compositor_state_deserializer_->GetLayerForEngineId(
+                    engine_layer->id()));
+          });
+    } else {
+      EXPECT_EQ(layer_tree_host_in_process_->GetLayerTree()->root_layer(),
+                nullptr);
+    }
+
+    // Viewport layers.
+    // Overscroll Elasticty Layer.
+    Layer* client_overscroll_elasticity_layer =
+        client_layer_tree->overscroll_elasticity_layer();
+    if (engine_layer_tree->overscroll_elasticity_layer()) {
+      int engine_overscroll_elasticity_layer_id =
+          engine_layer_tree->overscroll_elasticity_layer()->id();
+
+      EXPECT_LAYERS_EQ(engine_overscroll_elasticity_layer_id,
+                       client_overscroll_elasticity_layer);
+    } else {
+      EXPECT_EQ(client_overscroll_elasticity_layer, nullptr);
+    }
+
+    // PageScale Layer.
+    Layer* client_page_scale_layer = client_layer_tree->page_scale_layer();
+    if (engine_layer_tree->page_scale_layer()) {
+      int engine_page_scale_layer_id =
+          engine_layer_tree->page_scale_layer()->id();
+
+      EXPECT_LAYERS_EQ(engine_page_scale_layer_id, client_page_scale_layer);
+    } else {
+      EXPECT_EQ(client_page_scale_layer, nullptr);
+    }
+
+    // InnerViewportScroll Layer.
+    Layer* client_inner_viewport_layer =
+        client_layer_tree->inner_viewport_scroll_layer();
+    if (engine_layer_tree->inner_viewport_scroll_layer()) {
+      int engine_inner_viewport_layer_id =
+          engine_layer_tree->inner_viewport_scroll_layer()->id();
+
+      EXPECT_LAYERS_EQ(engine_inner_viewport_layer_id,
+                       client_inner_viewport_layer);
+    } else {
+      EXPECT_EQ(client_inner_viewport_layer, nullptr);
+    }
+
+    // OuterViewportScroll Layer.
+    Layer* client_outer_viewport_layer =
+        client_layer_tree->outer_viewport_scroll_layer();
+    if (engine_layer_tree->outer_viewport_scroll_layer()) {
+      int engine_outer_viewport_layer_id =
+          engine_layer_tree->outer_viewport_scroll_layer()->id();
+
+      EXPECT_LAYERS_EQ(engine_outer_viewport_layer_id,
+                       client_outer_viewport_layer);
+    } else {
+      EXPECT_EQ(client_outer_viewport_layer, nullptr);
+    }
+  }
+
+  void VerifyLayersAreIdentical(Layer* engine_layer, Layer* client_layer) {
+    ASSERT_NE(client_layer, nullptr);
+
+    LayerTree* client_layer_tree = layer_tree_host_in_process_->GetLayerTree();
+    EXPECT_EQ(client_layer_tree, client_layer->GetLayerTree());
+
+    // Parent.
+    if (engine_layer->parent()) {
+      int engine_parent_id = engine_layer->parent()->id();
+      EXPECT_LAYERS_EQ(engine_parent_id, client_layer->parent());
+    } else {
+      EXPECT_EQ(client_layer->parent(), nullptr);
+    }
+
+    // Mask Layers.
+    if (engine_layer->mask_layer()) {
+      int engine_mask_layer_id = engine_layer->mask_layer()->id();
+      EXPECT_LAYERS_EQ(engine_mask_layer_id, client_layer->mask_layer());
+    } else {
+      EXPECT_EQ(client_layer->mask_layer(), nullptr);
+    }
+
+    // Scroll parent.
+    if (engine_layer->scroll_parent()) {
+      int engine_scroll_parent_id = engine_layer->scroll_parent()->id();
+      EXPECT_LAYERS_EQ(engine_scroll_parent_id, client_layer->scroll_parent());
+    } else {
+      EXPECT_EQ(client_layer->scroll_parent(), nullptr);
+    }
+
+    // Clip parent.
+    if (engine_layer->clip_parent()) {
+      int engine_clip_parent_id = engine_layer->clip_parent()->id();
+      EXPECT_LAYERS_EQ(engine_clip_parent_id, client_layer->clip_parent());
+    } else {
+      EXPECT_EQ(client_layer->clip_parent(), nullptr);
+    }
+
+    // Scroll-clip layer.
+    if (engine_layer->scroll_clip_layer()) {
+      int scroll_clip_id = engine_layer->scroll_clip_layer()->id();
+      EXPECT_LAYERS_EQ(scroll_clip_id, client_layer->scroll_clip_layer());
+    } else {
+      EXPECT_EQ(client_layer->scroll_clip_layer(), nullptr);
+    }
+  }
+
+  // Engine setup.
+  std::unique_ptr<LayerTreeHostRemote> layer_tree_host_remote_;
+  StubLayerTreeHostClient layer_tree_host_client_remote_;
+
+  // Client setup.
+  std::unique_ptr<FakeLayerTreeHost> layer_tree_host_in_process_;
+  std::unique_ptr<CompositorStateDeserializer> compositor_state_deserializer_;
+  FakeLayerTreeHostClient layer_tree_host_client_client_;
+  TestTaskGraphRunner task_graph_runner_;
+
+  bool should_retain_client_scroll_ = false;
+  bool should_retain_client_scale_ = false;
+};
+
+TEST_F(CompositorStateDeserializerTest, BasicSync) {
+  // Set up a tree with a single node.
+  scoped_refptr<Layer> root_layer = Layer::Create();
+  layer_tree_host_remote_->GetLayerTree()->SetRootLayer(root_layer);
+
+  // Synchronize State and verify.
+  base::RunLoop().RunUntilIdle();
+  VerifyTreesAreIdentical();
+
+  // Swap the root layer.
+  scoped_refptr<Layer> new_root_layer = Layer::Create();
+  new_root_layer->AddChild(Layer::Create());
+  new_root_layer->AddChild(Layer::Create());
+  layer_tree_host_remote_->GetLayerTree()->SetRootLayer(new_root_layer);
+
+  // Synchronize State and verify.
+  base::RunLoop().RunUntilIdle();
+  VerifyTreesAreIdentical();
+  // Verify that we are no longer tracking the destroyed layer on the client.
+  EXPECT_EQ(
+      compositor_state_deserializer_->GetLayerForEngineId(root_layer->id()),
+      nullptr);
+
+  // Remove the root layer to change to a null tree.
+  layer_tree_host_remote_->GetLayerTree()->SetRootLayer(nullptr);
+
+  // Synchronize State and verify.
+  base::RunLoop().RunUntilIdle();
+  VerifyTreesAreIdentical();
+}
+
+TEST_F(CompositorStateDeserializerTest, ViewportLayers) {
+  scoped_refptr<Layer> root_layer = Layer::Create();
+  layer_tree_host_remote_->GetLayerTree()->SetRootLayer(root_layer);
+
+  scoped_refptr<Layer> overscroll_elasticity_layer = Layer::Create();
+  scoped_refptr<Layer> inner_viewport_scroll_layer = Layer::Create();
+  scoped_refptr<Layer> outer_viewport_scroll_layer = Layer::Create();
+  scoped_refptr<Layer> page_scale_layer = Layer::Create();
+  layer_tree_host_remote_->GetLayerTree()->RegisterViewportLayers(
+      overscroll_elasticity_layer, page_scale_layer,
+      inner_viewport_scroll_layer, outer_viewport_scroll_layer);
+
+  root_layer->AddChild(overscroll_elasticity_layer);
+  overscroll_elasticity_layer->AddChild(page_scale_layer);
+  page_scale_layer->AddChild(inner_viewport_scroll_layer);
+  inner_viewport_scroll_layer->AddChild(outer_viewport_scroll_layer);
+
+  // Synchronize State and verify.
+  base::RunLoop().RunUntilIdle();
+  VerifyTreesAreIdentical();
+}
+
+TEST_F(CompositorStateDeserializerTest, ScrollClipAndMaskLayers) {
+  /*   root -- A---C---D
+  /      |      \
+  /      |       E(MaskLayer)
+  /      ------B */
+  scoped_refptr<Layer> root_layer = Layer::Create();
+  layer_tree_host_remote_->GetLayerTree()->SetRootLayer(root_layer);
+
+  scoped_refptr<Layer> layer_a = Layer::Create();
+  scoped_refptr<Layer> layer_b = Layer::Create();
+  scoped_refptr<Layer> layer_c = Layer::Create();
+  scoped_refptr<Layer> layer_d = Layer::Create();
+  scoped_refptr<Layer> layer_e = Layer::Create();
+
+  root_layer->AddChild(layer_a);
+  root_layer->AddChild(layer_b);
+  layer_a->AddChild(layer_c);
+  layer_c->AddChild(layer_d);
+
+  layer_a->SetMaskLayer(layer_e.get());
+  layer_c->SetScrollParent(layer_b.get());
+  layer_c->SetScrollClipLayerId(root_layer->id());
+  layer_d->SetClipParent(layer_a.get());
+
+  // Synchronize State and verify.
+  base::RunLoop().RunUntilIdle();
+  VerifyTreesAreIdentical();
+}
+
+TEST_F(CompositorStateDeserializerTest, ReconcileScrollAndScale) {
+  scoped_refptr<Layer> root_layer = Layer::Create();
+  layer_tree_host_remote_->GetLayerTree()->SetRootLayer(root_layer);
+
+  // Set scroll offset.
+  scoped_refptr<Layer> scroll_layer = Layer::Create();
+  root_layer->AddChild(scroll_layer);
+  gfx::ScrollOffset engine_offset(4, 3);
+  scroll_layer->SetScrollOffset(engine_offset);
+
+  // Set page scale.
+  float engine_page_scale = 0.5f;
+  layer_tree_host_remote_->GetLayerTree()->SetPageScaleFactorAndLimits(
+      engine_page_scale, 1.0, 1.0);
+
+  // Synchronize State and verify that the engine values are used.
+  base::RunLoop().RunUntilIdle();
+  VerifyTreesAreIdentical();
+
+  EXPECT_EQ(engine_page_scale,
+            layer_tree_host_in_process_->GetLayerTree()->page_scale_factor());
+  EXPECT_EQ(engine_offset, compositor_state_deserializer_
+                               ->GetLayerForEngineId(scroll_layer->id())
+                               ->scroll_offset());
+
+  // Now reset the scroll offset and page scale and force-retain the client
+  // values.
+  gfx::ScrollOffset new_engine_offset(2, 2);
+  scroll_layer->SetScrollOffset(new_engine_offset);
+  float new_engine_page_scale = 0.8f;
+  layer_tree_host_remote_->GetLayerTree()->SetPageScaleFactorAndLimits(
+      new_engine_page_scale, 1.0, 1.0);
+  should_retain_client_scroll_ = true;
+  should_retain_client_scale_ = true;
+
+  // Synchronize State and verify that the client values are retained.
+  base::RunLoop().RunUntilIdle();
+  VerifyTreesAreIdentical();
+
+  EXPECT_EQ(engine_page_scale,
+            layer_tree_host_in_process_->GetLayerTree()->page_scale_factor());
+  EXPECT_EQ(engine_offset, compositor_state_deserializer_
+                               ->GetLayerForEngineId(scroll_layer->id())
+                               ->scroll_offset());
+}
+
+TEST_F(CompositorStateDeserializerTest, PropertyTreesAreIdentical) {
+  // Override the LayerFactory. This is necessary to ensure the layer ids
+  // tracked in PropertyTrees on the engine and client are identical.
+  compositor_state_deserializer_->SetLayerFactoryForTesting(
+      base::MakeUnique<RemoteClientLayerFactory>());
+
+  scoped_refptr<Layer> root_layer = Layer::Create();
+  root_layer->SetBounds(gfx::Size(10, 10));
+  layer_tree_host_remote_->GetLayerTree()->SetRootLayer(root_layer);
+
+  scoped_refptr<Layer> child1 = Layer::Create();
+  root_layer->AddChild(child1);
+  gfx::Transform transform;
+  transform.Translate(gfx::Vector2dF(5, 4));
+  child1->SetTransform(transform);
+  child1->SetMasksToBounds(true);
+
+  scoped_refptr<Layer> child2 = Layer::Create();
+  root_layer->AddChild(child2);
+  child2->SetBounds(gfx::Size(5, 5));
+  child2->SetScrollOffset(gfx::ScrollOffset(3, 4));
+  child2->SetScrollParent(child1.get());
+  child2->SetUserScrollable(true, true);
+
+  scoped_refptr<Layer> grandchild11 = Layer::Create();
+  child1->AddChild(grandchild11);
+  grandchild11->SetClipParent(root_layer.get());
+
+  scoped_refptr<Layer> grandchild21 = Layer::Create();
+  child2->AddChild(grandchild21);
+  grandchild21->SetScrollClipLayerId(child1->id());
+  grandchild21->SetOpacity(0.5);
+
+  // Synchronize State and verify.
+  base::RunLoop().RunUntilIdle();
+  VerifyTreesAreIdentical();
+  EXPECT_EQ(root_layer->id(), layer_tree_host_in_process_->root_layer()->id());
+
+  // Sanity test to ensure that the PropertyTrees generated from the Layers on
+  // the client and engine are identical.
+  layer_tree_host_remote_->GetLayerTree()->BuildPropertyTreesForTesting();
+  PropertyTrees* engine_property_trees =
+      layer_tree_host_remote_->GetLayerTree()->property_trees();
+
+  layer_tree_host_in_process_->BuildPropertyTreesForTesting();
+  PropertyTrees* client_property_trees =
+      layer_tree_host_in_process_->property_trees();
+
+  EXPECT_EQ(*engine_property_trees, *client_property_trees);
+}
+
+}  // namespace
+}  // namespace cc