Avoid exposing cc::Layer tree to CompositorProxy

third_party/WebKit/Source/platform/graphics/CompositorMutatorClientTest.cpp

Index: third_party/WebKit/Source/platform/graphics/CompositorMutatorClientTest.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/CompositorMutatorClientTest.cpp b/third_party/WebKit/Source/platform/graphics/CompositorMutatorClientTest.cpp
index 0c10d6476898f9653f5a072f21a8d7181705e8d8..c9285aaa81370a02c433dc2527fc8971888e0b73 100644
--- a/third_party/WebKit/Source/platform/graphics/CompositorMutatorClientTest.cpp
+++ b/third_party/WebKit/Source/platform/graphics/CompositorMutatorClientTest.cpp
@@ -6,6 +6,18 @@
 
 #include <memory>
 #include "base/callback.h"
+#include "base/message_loop/message_loop.h"
+#include "base/time/time.h"
+#include "cc/test/fake_compositor_frame_sink.h"
+#include "cc/test/fake_impl_task_runner_provider.h"
+#include "cc/test/fake_layer_tree_host_impl.h"
+#include "cc/test/test_shared_bitmap_manager.h"
+#include "cc/test/test_task_graph_runner.h"
+#include "cc/trees/layer_tree_host_impl.h"
+#include "cc/trees/layer_tree_impl.h"
+#include "platform/graphics/CompositorElementId.h"
+#include "platform/graphics/CompositorMutableState.h"
+#include "platform/graphics/CompositorMutableStateProvider.h"
 #include "platform/graphics/CompositorMutation.h"
 #include "platform/graphics/CompositorMutationsTarget.h"
 #include "platform/graphics/CompositorMutator.h"
@@ -28,13 +40,43 @@ class StubCompositorMutator : public CompositorMutator {
   }
 };
 
-class MockCompositoMutationsTarget : public CompositorMutationsTarget {
+class MockCompositorMutator : public CompositorMutator {
+ public:
+  MOCK_METHOD2(Mutate, bool(double, CompositorMutableStateProvider*));
+};
+
+class MockCompositorMutationsTarget : public CompositorMutationsTarget {
  public:
   MOCK_METHOD1(ApplyMutations, void(CompositorMutations*));
 };
 
-TEST(CompositorMutatorClient, CallbackForNonNullMutationsShouldApply) {
-  MockCompositoMutationsTarget target;
+class CompositorMutatorClientTest : public testing::Test {
+ public:
+  CompositorMutatorClientTest()
+      : compositor_frame_sink_(cc::FakeCompositorFrameSink::Create3d()) {
+    cc::LayerTreeSettings settings;
+    settings.layer_transforms_should_scale_layer_contents = true;
+    host_impl_.reset(new cc::FakeLayerTreeHostImpl(
+        settings, &task_runner_provider_, &task_graph_runner_));
+    host_impl_->SetVisible(true);
+    EXPECT_TRUE(host_impl_->InitializeRenderer(compositor_frame_sink_.get()));
+  }
+
+  cc::FakeLayerTreeHostImpl& hostImpl() { return *host_impl_; }
+
+ private:
+  // The cc testing machinery has fairly deep dependency on having a main
+  // message loop (one example is the task runner provider). We construct one
+  // here so that it's installed in TLA and can be found by other cc classes.
+  base::MessageLoop message_loop_;
+  cc::TestTaskGraphRunner task_graph_runner_;
+  cc::FakeImplTaskRunnerProvider task_runner_provider_;
+  std::unique_ptr<cc::FakeCompositorFrameSink> compositor_frame_sink_;
+  std::unique_ptr<cc::FakeLayerTreeHostImpl> host_impl_;
+};
+
+TEST_F(CompositorMutatorClientTest, CallbackForNonNullMutationsShouldApply) {
+  MockCompositorMutationsTarget target;
 
   CompositorMutatorClient client(new StubCompositorMutator, &target);
   std::unique_ptr<CompositorMutations> mutations =
@@ -45,13 +87,99 @@ TEST(CompositorMutatorClient, CallbackForNonNullMutationsShouldApply) {
   client.TakeMutations().Run();
 }
 
-TEST(CompositorMutatorClient, CallbackForNullMutationsShouldBeNoop) {
-  MockCompositoMutationsTarget target;
+TEST_F(CompositorMutatorClientTest, CallbackForNullMutationsShouldBeNoop) {
+  MockCompositorMutationsTarget target;
   CompositorMutatorClient client(new StubCompositorMutator, &target);
 
   EXPECT_CALL(target, ApplyMutations(_)).Times(0);
   EXPECT_TRUE(client.TakeMutations().is_null());
 }
 
+TEST_F(CompositorMutatorClientTest, MutateOneProxy) {
+  MockCompositorMutationsTarget target;
+  MockCompositorMutator mutator;
+  CompositorMutatorClient client(&mutator, &target);
+
+  uint64_t proxyId = 12;
+  uint64_t elementId = 15;
+  uint32_t mutableProperties = CompositorMutableProperty::kOpacity |
+                               CompositorMutableProperty::kTransform |
+                               CompositorMutableProperty::kScrollLeft |
+                               CompositorMutableProperty::kScrollTop;
+  client.RegisterCompositorProxy(proxyId, elementId, mutableProperties);
+
+  std::unique_ptr<cc::LayerImpl> root =
+      cc::LayerImpl::Create(hostImpl().active_tree(), 42);
+  std::unique_ptr<cc::LayerImpl> scroll =
+      cc::LayerImpl::Create(hostImpl().active_tree(), 11);
+  cc::LayerImpl* scrollLayer = scroll.get();
+  cc::LayerImpl* rootLayer = root.get();
+
+  root->test_properties()->AddChild(std::move(scroll));
+  root->SetElementId(
+      CreateCompositorElementId(elementId, CompositorSubElementId::kPrimary));
+  root->SetMutableProperties(CompositorMutableProperty::kOpacity |
+                             CompositorMutableProperty::kTransform);
+
+  scrollLayer->SetScrollClipLayer(root->id());
+  scrollLayer->test_properties()->transform = gfx::Transform();
+  scrollLayer->SetPosition(gfx::PointF());
+  scrollLayer->SetBounds(gfx::Size(100, 100));
+  scrollLayer->SetDrawsContent(true);
+  scrollLayer->SetElementId(
+      CreateCompositorElementId(elementId, CompositorSubElementId::kScroll));
+  scrollLayer->SetMutableProperties(CompositorMutableProperty::kScrollLeft |
+                                    CompositorMutableProperty::kScrollTop);
+
+  hostImpl().SetViewportSize(scrollLayer->bounds());
+  hostImpl().active_tree()->SetRootLayerForTesting(std::move(root));
+  hostImpl().UpdateNumChildrenAndDrawPropertiesForActiveTree();
+
+  gfx::Transform zero(0, 0, 0, 0, 0, 0);
+  EXPECT_CALL(mutator, Mutate(_, _))
+      .WillOnce(testing::Invoke(
+          [zero, proxyId](double now,
+                          CompositorMutableStateProvider* stateProvider) {
+            std::unique_ptr<CompositorMutableState> mutableState =
+                stateProvider->GetMutableStateFor(proxyId);
+            EXPECT_TRUE(mutableState);
+            EXPECT_EQ(gfx::Transform().ToString(),
+                      gfx::Transform(mutableState->Transform()).ToString());
+            EXPECT_EQ(0, mutableState->ScrollLeft());
+            EXPECT_EQ(0, mutableState->ScrollTop());
+
+            mutableState->SetOpacity(0.5);
+            mutableState->SetTransform(zero.matrix());
+            mutableState->SetScrollLeft(10);
+            mutableState->SetScrollTop(20);
+            return false;
+          }));
+  client.Mutate(base::TimeTicks(), hostImpl().active_tree());
+
+  EXPECT_EQ(0.5, rootLayer->Opacity());
+  EXPECT_EQ(zero.ToString(), rootLayer->Transform().ToString());
+  EXPECT_EQ(10, scrollLayer->CurrentScrollOffset().x());
+  EXPECT_EQ(20, scrollLayer->CurrentScrollOffset().y());
+
+  EXPECT_CALL(target, ApplyMutations(_))
+      .WillOnce(
+          testing::Invoke([elementId, zero](CompositorMutations* mutations) {
+            EXPECT_EQ(1ul, mutations->map.size());
+            const CompositorMutation& mutation =
+                *mutations->map.Find(elementId)->value;
+            EXPECT_TRUE(mutation.IsOpacityMutated());
+            EXPECT_TRUE(mutation.IsTransformMutated());
+            EXPECT_TRUE(mutation.IsScrollLeftMutated());
+            EXPECT_TRUE(mutation.IsScrollTopMutated());
+
+            EXPECT_EQ(0.5, mutation.Opacity());
+            EXPECT_EQ(zero.ToString(),
+                      gfx::Transform(mutation.Transform()).ToString());
+            EXPECT_EQ(10, mutation.ScrollLeft());
+            EXPECT_EQ(20, mutation.ScrollTop());
+          }));
+  client.TakeMutations().Run();
+}
+
 }  // namespace
 }  // namespace blink