Implement CSS: scroll-boundary-behavior

cc/trees/layer_tree_host_impl_unittest.cc

Index: cc/trees/layer_tree_host_impl_unittest.cc
diff --git a/cc/trees/layer_tree_host_impl_unittest.cc b/cc/trees/layer_tree_host_impl_unittest.cc
index d0a6196fb6cecc095c494f11c1b324f603e7d1ff..f7629dd0bc8164ff0654d5d5b130b0836147f5d3 100644
--- a/cc/trees/layer_tree_host_impl_unittest.cc
+++ b/cc/trees/layer_tree_host_impl_unittest.cc
@@ -1425,6 +1425,120 @@ TEST_F(LayerTreeHostImplTest, ScrollByReturnsCorrectValue) {
           .did_scroll);
 }
 
+TEST_F(LayerTreeHostImplTest, ScrollBoundaryBehaviorPreventsPropagation) {
+  LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(200, 200));
+  host_impl_->SetViewportSize(gfx::Size(100, 100));
+
+  gfx::Size overflow_size(400, 400);
+  ASSERT_EQ(1u, scroll_layer->test_properties()->children.size());
+  LayerImpl* overflow = scroll_layer->test_properties()->children[0];
+  overflow->SetBounds(overflow_size);
+  overflow->SetScrollable(gfx::Size(100, 100));
+  overflow->SetElementId(LayerIdToElementIdForTesting(overflow->id()));
+  overflow->layer_tree_impl()
+      ->property_trees()
+      ->scroll_tree.UpdateScrollOffsetBaseForTesting(overflow->element_id(),
+                                                     gfx::ScrollOffset());
+  overflow->SetPosition(gfx::PointF(40, 40));
+  host_impl_->active_tree()->BuildPropertyTreesForTesting();
+  scroll_layer->SetCurrentScrollOffset(gfx::ScrollOffset(30, 30));
+
+  DrawFrame();
+  gfx::Point scroll_position(50, 50);
+
+  // ScrollBoundaryBehaviorTypeAuto shouldn't prevent scroll propagation.
+  EXPECT_EQ(
+      InputHandler::SCROLL_ON_IMPL_THREAD,
+      host_impl_
+          ->ScrollBegin(BeginState(scroll_position).get(), InputHandler::WHEEL)
+          .thread);
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(30, 30), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(), overflow->CurrentScrollOffset());
+
+  gfx::Vector2dF x_dominant_delta(-10, -5);
+  gfx::Vector2dF y_dominant_delta(-5, -10);
+  host_impl_->ScrollBy(UpdateState(scroll_position, x_dominant_delta).get());
+  host_impl_->ScrollEnd(EndState().get());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(20, 25), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), overflow->CurrentScrollOffset());
+
+  overflow->test_properties()->scroll_boundary_behavior =
+      ScrollBoundaryBehavior(
+          ScrollBoundaryBehavior::kScrollBoundaryBehaviorTypeNone,
+          ScrollBoundaryBehavior::kScrollBoundaryBehaviorTypeAuto);
+  host_impl_->active_tree()->BuildPropertyTreesForTesting();
+
+  DrawFrame();
+
+  // ScrollBoundaryBehaviorNone on x should prevent x-dominant-scroll
+  // propagation.
+  EXPECT_EQ(
+      InputHandler::SCROLL_ON_IMPL_THREAD,
+      host_impl_
+          ->ScrollBegin(BeginState(scroll_position).get(), InputHandler::WHEEL)
+          .thread);
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(20, 25), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), overflow->CurrentScrollOffset());
+
+  host_impl_->ScrollBy(UpdateState(scroll_position, x_dominant_delta).get());
+  host_impl_->ScrollEnd(EndState().get());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(20, 25), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), overflow->CurrentScrollOffset());
+
+  // ScrollBoundaryBehaviorNone on x shouldn't prevent y-dominant-scroll
+  // propagation.
+  EXPECT_EQ(
+      InputHandler::SCROLL_ON_IMPL_THREAD,
+      host_impl_
+          ->ScrollBegin(BeginState(scroll_position).get(), InputHandler::WHEEL)
+          .thread);
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(20, 25), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), overflow->CurrentScrollOffset());
+
+  host_impl_->ScrollBy(UpdateState(scroll_position, y_dominant_delta).get());
+  host_impl_->ScrollEnd(EndState().get());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(15, 15), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), overflow->CurrentScrollOffset());
+
+  overflow->test_properties()->scroll_boundary_behavior =
+      ScrollBoundaryBehavior(
+          ScrollBoundaryBehavior::kScrollBoundaryBehaviorTypeAuto,
+          ScrollBoundaryBehavior::kScrollBoundaryBehaviorTypeNone);
+  host_impl_->active_tree()->BuildPropertyTreesForTesting();
+
+  DrawFrame();
+
+  // ScrollBoundaryBehaviorNone on y shouldn't prevent x-dominant-scroll
+  // propagation.
+  EXPECT_EQ(
+      InputHandler::SCROLL_ON_IMPL_THREAD,
+      host_impl_
+          ->ScrollBegin(BeginState(scroll_position).get(), InputHandler::WHEEL)
+          .thread);
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(15, 15), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), overflow->CurrentScrollOffset());
+
+  host_impl_->ScrollBy(UpdateState(scroll_position, x_dominant_delta).get());
+  host_impl_->ScrollEnd(EndState().get());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(5, 10), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), overflow->CurrentScrollOffset());
+
+  // ScrollBoundaryBehaviorNone on y should prevent y-dominant-scroll
+  // propagation.
+  EXPECT_EQ(
+      InputHandler::SCROLL_ON_IMPL_THREAD,
+      host_impl_
+          ->ScrollBegin(BeginState(scroll_position).get(), InputHandler::WHEEL)
+          .thread);
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(5, 10), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), overflow->CurrentScrollOffset());
+
+  host_impl_->ScrollBy(UpdateState(scroll_position, y_dominant_delta).get());
+  host_impl_->ScrollEnd(EndState().get());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(5, 10), scroll_layer->CurrentScrollOffset());
+  EXPECT_VECTOR_EQ(gfx::Vector2dF(0, 0), overflow->CurrentScrollOffset());
+}
+
 TEST_F(LayerTreeHostImplTest, ScrollWithUserUnscrollableLayers) {
   LayerImpl* scroll_layer = SetupScrollAndContentsLayers(gfx::Size(200, 200));
   host_impl_->SetViewportSize(gfx::Size(100, 100));