Generalize layer mirroring for phantom windows

ui/compositor/layer_unittest.cc

Index: ui/compositor/layer_unittest.cc
diff --git a/ui/compositor/layer_unittest.cc b/ui/compositor/layer_unittest.cc
index 3f12bca1ac47343a78d2afa1996b6498e28df714..46a33b3391c7c4ac437c19c475a210c4d398aa23 100644
--- a/ui/compositor/layer_unittest.cc
+++ b/ui/compositor/layer_unittest.cc
@@ -747,6 +747,131 @@ TEST_F(LayerWithRealCompositorTest, HierarchyNoTexture) {
   EXPECT_TRUE(d3.painted());
 }
 
+TEST_F(LayerWithDelegateTest, Cloning) {
+  std::unique_ptr<Layer> layer(CreateLayer(LAYER_SOLID_COLOR));
+
+  gfx::Transform transform;
+  transform.Scale(2, 1);
+  transform.Translate(10, 5);
+
+  layer->SetTransform(transform);
+  layer->SetColor(SK_ColorRED);
+  layer->SetLayerInverted(true);
+
+  auto clone = layer->Clone();
+
+  // Cloning preserves layer state.
+  EXPECT_EQ(transform, clone->GetTargetTransform());
+  EXPECT_EQ(SK_ColorRED, clone->background_color());
+  EXPECT_EQ(SK_ColorRED, clone->GetTargetColor());
+  EXPECT_TRUE(clone->layer_inverted());
+
+  layer->SetTransform(gfx::Transform());
+  layer->SetColor(SK_ColorGREEN);
+  layer->SetLayerInverted(false);
+
+  // The clone is an independent copy, so state changes do not propagate.
+  EXPECT_EQ(transform, clone->GetTargetTransform());
+  EXPECT_EQ(SK_ColorRED, clone->background_color());
+  EXPECT_EQ(SK_ColorRED, clone->GetTargetColor());
+  EXPECT_TRUE(clone->layer_inverted());
+
+  constexpr SkColor kTransparent = SK_ColorTRANSPARENT;
+  layer->SetColor(kTransparent);
+  layer->SetFillsBoundsOpaquely(false);
+  // Color and opaqueness targets should be preserved during cloning, even after
+  // switching away from solid color content.
+  layer->SwitchCCLayerForTest();
+
+  clone = layer->Clone();
+
+  // The clone is a copy of the latest state.
+  EXPECT_TRUE(clone->GetTargetTransform().IsIdentity());
+  EXPECT_EQ(kTransparent, clone->background_color());
+  EXPECT_EQ(kTransparent, clone->GetTargetColor());
+  EXPECT_FALSE(clone->layer_inverted());
+  EXPECT_FALSE(clone->fills_bounds_opaquely());
+
+  layer.reset(CreateLayer(LAYER_SOLID_COLOR));
+  layer->SetVisible(true);
+  layer->SetOpacity(1.0f);
+  layer->SetColor(SK_ColorRED);
+
+  ScopedLayerAnimationSettings settings(layer->GetAnimator());
+  layer->SetVisible(false);
+  layer->SetOpacity(0.0f);
+  layer->SetColor(SK_ColorGREEN);
+
+  EXPECT_TRUE(layer->visible());
+  EXPECT_EQ(1.0f, layer->opacity());
+  EXPECT_EQ(SK_ColorRED, layer->background_color());
+
+  clone = layer->Clone();
+
+  // Cloning copies animation targets.
+  EXPECT_FALSE(clone->visible());
+  EXPECT_EQ(0.0f, clone->opacity());
+  EXPECT_EQ(SK_ColorGREEN, clone->background_color());
+}
+
+TEST_F(LayerWithDelegateTest, Mirroring) {
+  std::unique_ptr<Layer> root(CreateNoTextureLayer(gfx::Rect(0, 0, 100, 100)));
+  std::unique_ptr<Layer> child(CreateLayer(LAYER_TEXTURED));
+
+  const gfx::Rect bounds(0, 0, 50, 50);
+  child->SetBounds(bounds);
+  child->SetVisible(true);
+
+  DrawTreeLayerDelegate delegate(child->bounds());
+  child->set_delegate(&delegate);
+
+  const auto mirror = child->Mirror();
+
+  // Bounds and visibility are preserved.
+  EXPECT_EQ(bounds, mirror->bounds());
+  EXPECT_TRUE(mirror->visible());
+
+  root->Add(child.get());
+  root->Add(mirror.get());
+
+  DrawTree(root.get());
+  EXPECT_TRUE(delegate.painted());
+  delegate.Reset();
+
+  // Both layers should be clean.
+  EXPECT_TRUE(child->damaged_region_for_testing().IsEmpty());
+  EXPECT_TRUE(mirror->damaged_region_for_testing().IsEmpty());
+
+  const gfx::Rect damaged_rect(10, 10, 20, 20);
+  EXPECT_TRUE(child->SchedulePaint(damaged_rect));
+  EXPECT_EQ(damaged_rect, child->damaged_region_for_testing().bounds());
+
+  DrawTree(root.get());
+  EXPECT_TRUE(delegate.painted());
+  delegate.Reset();
+
+  // Damage should be propagated to the mirror.
+  EXPECT_EQ(damaged_rect, mirror->damaged_region_for_testing().bounds());
+  EXPECT_TRUE(child->damaged_region_for_testing().IsEmpty());
+
+  DrawTree(root.get());
+  EXPECT_TRUE(delegate.painted());
+
+  // Mirror should be clean.
+  EXPECT_TRUE(mirror->damaged_region_for_testing().IsEmpty());
+
+  // Bounds are not synchronized by default.
+  const gfx::Rect new_bounds(10, 10, 10, 10);
+  child->SetBounds(new_bounds);
+  EXPECT_EQ(bounds, mirror->bounds());
+  child->SetBounds(bounds);
+
+  // Bounds should be synchronized if requested.
+  child->set_sync_bounds(true);
+  child->SetBounds(new_bounds);
+  EXPECT_EQ(new_bounds, mirror->bounds());
+}
+
 class LayerWithNullDelegateTest : public LayerWithDelegateTest {
  public:
   LayerWithNullDelegateTest() {}
@@ -1721,6 +1846,41 @@ TEST_F(LayerWithDelegateTest, ExternalContent) {
   EXPECT_NE(before.get(), child->cc_layer_for_testing());
 }
 
+TEST_F(LayerWithDelegateTest, ExternalContentMirroring) {
+  std::unique_ptr<Layer> layer(CreateLayer(LAYER_SOLID_COLOR));
+
+  const auto satisfy_callback = base::Bind(&FakeSatisfyCallback);
+  const auto require_callback = base::Bind(&FakeRequireCallback);
+
+  cc::SurfaceId surface_id(cc::FrameSinkId(0, 1), cc::LocalFrameId(2, 3));
+  layer->SetShowSurface(surface_id, satisfy_callback, require_callback,
+                        gfx::Size(10, 10), 1.0f, gfx::Size(10, 10));
+
+  const auto mirror = layer->Mirror();
+  auto* const cc_layer = mirror->cc_layer_for_testing();
+  const auto* surface = static_cast<cc::SurfaceLayer*>(cc_layer);
+
+  // Mirroring preserves surface state.
+  EXPECT_EQ(surface_id, surface->surface_id());
+  EXPECT_TRUE(satisfy_callback.Equals(surface->satisfy_callback()));
+  EXPECT_TRUE(require_callback.Equals(surface->require_callback()));
+  EXPECT_EQ(gfx::Size(10, 10), surface->surface_size());
+  EXPECT_EQ(1.0f, surface->surface_scale());
+
+  surface_id = cc::SurfaceId(cc::FrameSinkId(1, 2), cc::LocalFrameId(3, 4));
+  layer->SetShowSurface(surface_id, satisfy_callback, require_callback,
+                        gfx::Size(20, 20), 2.0f, gfx::Size(20, 20));
+
+  // A new cc::Layer should be created for the mirror.
+  EXPECT_NE(cc_layer, mirror->cc_layer_for_testing());
+  surface = static_cast<cc::SurfaceLayer*>(mirror->cc_layer_for_testing());
+
+  // Surface updates propagate to the mirror.
+  EXPECT_EQ(surface_id, surface->surface_id());
+  EXPECT_EQ(gfx::Size(20, 20), surface->surface_size());
+  EXPECT_EQ(2.0f, surface->surface_scale());
+}
+
 // Verifies that layer filters still attached after changing implementation
 // layer.
 TEST_F(LayerWithDelegateTest, LayerFiltersSurvival) {