cc/layers/painted_scrollbar_layer_impl_unittest.cc

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "cc/layers/painted_scrollbar_layer_impl.h"

#include <stddef.h>

#include "cc/resources/ui_resource_bitmap.h"
#include "cc/test/layer_tree_impl_test_base.h"
#include "components/viz/common/quads/draw_quad.h"
#include "components/viz/common/quads/solid_color_draw_quad.h"
#include "components/viz/common/quads/texture_draw_quad.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace cc {
namespace {

TEST(PaintedScrollbarLayerImplTest, Occlusion) {
  gfx::Size layer_size(10, 1000);
  float scale = 2.f;
  gfx::Size scaled_layer_size(20, 2000);
  gfx::Size viewport_size(1000, 1000);
  float painted_opacity_ = 0.2f;

  LayerTreeImplTestBase impl;

  SkBitmap thumb_sk_bitmap;
  thumb_sk_bitmap.allocN32Pixels(10, 10);
  thumb_sk_bitmap.setImmutable();
  UIResourceId thumb_uid = 5;
  UIResourceBitmap thumb_bitmap(thumb_sk_bitmap);
  impl.host_impl()->CreateUIResource(thumb_uid, thumb_bitmap);

  SkBitmap track_and_buttons_sk_bitmap;
  track_and_buttons_sk_bitmap.allocN32Pixels(10, 10);
  track_and_buttons_sk_bitmap.setImmutable();
  UIResourceId track_and_buttons_uid = 6;
  UIResourceBitmap track_and_buttons_bitmap(track_and_buttons_sk_bitmap);
  impl.host_impl()->CreateUIResource(track_and_buttons_uid,
                                     track_and_buttons_bitmap);

  ScrollbarOrientation orientation = ScrollbarOrientation::kVertical;

  PaintedScrollbarLayerImpl* scrollbar_layer_impl =
      impl.AddLayerInActiveTree<PaintedScrollbarLayerImpl>(orientation, false,
                                                           false);
  scrollbar_layer_impl->SetBounds(layer_size);
  scrollbar_layer_impl->SetContentsOpaque(true);
  scrollbar_layer_impl->set_internal_contents_scale_and_bounds(
      scale, scaled_layer_size);
  scrollbar_layer_impl->SetDrawsContent(true);
  scrollbar_layer_impl->SetThumbThickness(layer_size.width());
  scrollbar_layer_impl->SetThumbLength(500);
  scrollbar_layer_impl->SetTrackRect(gfx::Rect(0, 0, 15, layer_size.height()));
  scrollbar_layer_impl->SetCurrentPos(100.f / 4);
  scrollbar_layer_impl->SetClipLayerLength(100.f);
  scrollbar_layer_impl->SetScrollLayerLength(200.f);
  scrollbar_layer_impl->set_track_and_buttons_ui_resource_id(
      track_and_buttons_uid);
  scrollbar_layer_impl->set_thumb_ui_resource_id(thumb_uid);
  scrollbar_layer_impl->SetScrollbarPaintedOpacity(painted_opacity_);
  CopyProperties(impl.root_layer(), scrollbar_layer_impl);

  impl.CalcDrawProps(viewport_size);

  gfx::Rect thumb_rect = scrollbar_layer_impl->ComputeThumbQuadRect();
  EXPECT_EQ(gfx::Rect(0, 500 / 4, 10, layer_size.height() / 2), thumb_rect);

  {
    SCOPED_TRACE("No occlusion");
    gfx::Rect occluded;
    impl.AppendQuadsWithOcclusion(scrollbar_layer_impl, occluded);

    size_t partially_occluded_count = 0;
    VerifyQuadsAreOccluded(impl.quad_list(), occluded,
                           &partially_occluded_count);
    EXPECT_EQ(2u, impl.quad_list().size());
    EXPECT_EQ(0u, partially_occluded_count);

    // Note: this is also testing that the thumb and track are both
    // scaled by the internal contents scale.  It's not occlusion-related
    // but is easy to verify here.
    const viz::DrawQuad* thumb_draw_quad = impl.quad_list().ElementAt(0);
    const viz::DrawQuad* track_and_buttons_draw_quad =
        impl.quad_list().ElementAt(1);

    EXPECT_EQ(viz::DrawQuad::Material::kTextureContent,
              thumb_draw_quad->material);
    EXPECT_EQ(viz::DrawQuad::Material::kTextureContent,
              track_and_buttons_draw_quad->material);

    const viz::TextureDrawQuad* thumb_quad =
        viz::TextureDrawQuad::MaterialCast(thumb_draw_quad);
    const viz::TextureDrawQuad* track_and_buttons_quad =
        viz::TextureDrawQuad::MaterialCast(track_and_buttons_draw_quad);

    gfx::Rect scaled_thumb_rect = gfx::ScaleToEnclosingRect(thumb_rect, scale);
    EXPECT_EQ(track_and_buttons_quad->rect, gfx::Rect(scaled_layer_size));
    EXPECT_EQ(scrollbar_layer_impl->contents_opaque(),
              track_and_buttons_quad->shared_quad_state->are_contents_opaque);
    EXPECT_EQ(track_and_buttons_quad->visible_rect,
              gfx::Rect(scaled_layer_size));
    EXPECT_FALSE(track_and_buttons_quad->needs_blending);
    EXPECT_EQ(thumb_quad->rect, scaled_thumb_rect);
    EXPECT_EQ(thumb_quad->visible_rect, scaled_thumb_rect);
    EXPECT_TRUE(thumb_quad->needs_blending);
    EXPECT_FALSE(thumb_quad->shared_quad_state->are_contents_opaque);

    EXPECT_EQ(painted_opacity_, thumb_quad->shared_quad_state->opacity);
    EXPECT_EQ(1.f, track_and_buttons_quad->shared_quad_state->opacity);
  }

  {
    SCOPED_TRACE("Full occlusion");
    gfx::Rect occluded(scrollbar_layer_impl->visible_layer_rect());
    impl.AppendQuadsWithOcclusion(scrollbar_layer_impl, occluded);

    VerifyQuadsExactlyCoverRect(impl.quad_list(), gfx::Rect());
    EXPECT_EQ(impl.quad_list().size(), 0u);
  }

  {
    SCOPED_TRACE("Partial occlusion");
    gfx::Rect occluded(0, 0, 5, 1000);
    impl.AppendQuadsWithOcclusion(scrollbar_layer_impl, occluded);

    size_t partially_occluded_count = 0;
    VerifyQuadsAreOccluded(impl.quad_list(), occluded,
                           &partially_occluded_count);
    // The layer outputs two quads, which is partially occluded.
    EXPECT_EQ(2u, impl.quad_list().size());
    EXPECT_EQ(2u, partially_occluded_count);
  }
}

TEST(PaintedScrollbarLayerImplTest, Occlusion_SolidColorThumbNinePatchTrack) {
  gfx::Size layer_size(15, 1000);
  float scale = 2.f;
  gfx::Size scaled_layer_size(30, 2000);
  gfx::Size viewport_size(1000, 1000);

  LayerTreeImplTestBase impl;

  SkBitmap thumb_sk_bitmap;
  thumb_sk_bitmap.allocN32Pixels(10, 10);
  thumb_sk_bitmap.setImmutable();
  UIResourceId thumb_uid = 5;
  UIResourceBitmap thumb_bitmap(thumb_sk_bitmap);
  impl.host_impl()->CreateUIResource(thumb_uid, thumb_bitmap);

  SkBitmap track_and_buttons_sk_bitmap;
  track_and_buttons_sk_bitmap.allocN32Pixels(10, 10);
  track_and_buttons_sk_bitmap.setImmutable();
  UIResourceId track_and_buttons_uid = 6;
  UIResourceBitmap track_and_buttons_bitmap(track_and_buttons_sk_bitmap);
  impl.host_impl()->CreateUIResource(track_and_buttons_uid,
                                     track_and_buttons_bitmap);

  ScrollbarOrientation orientation = ScrollbarOrientation::kVertical;

  PaintedScrollbarLayerImpl* scrollbar_layer_impl =
      impl.AddLayerInActiveTree<PaintedScrollbarLayerImpl>(orientation, false,
                                                           false);
  scrollbar_layer_impl->SetBounds(layer_size);
  scrollbar_layer_impl->SetContentsOpaque(true);
  scrollbar_layer_impl->set_internal_contents_scale_and_bounds(
      scale, scaled_layer_size);
  scrollbar_layer_impl->SetDrawsContent(true);
  scrollbar_layer_impl->SetThumbThickness(11);
  scrollbar_layer_impl->SetThumbLength(500);
  scrollbar_layer_impl->SetTrackRect(gfx::Rect(0, 0, 15, layer_size.height()));
  scrollbar_layer_impl->SetCurrentPos(100.f / 4);
  scrollbar_layer_impl->SetClipLayerLength(100.f);
  scrollbar_layer_impl->SetScrollLayerLength(200.f);
  scrollbar_layer_impl->set_track_and_buttons_ui_resource_id(
      track_and_buttons_uid);
  scrollbar_layer_impl->SetThumbColor(SkColors::kRed);
  CopyProperties(impl.root_layer(), scrollbar_layer_impl);

  impl.CalcDrawProps(viewport_size);

  gfx::Rect thumb_rect = scrollbar_layer_impl->ComputeThumbQuadRect();
  EXPECT_EQ(gfx::Rect(2, 500 / 4, 11, layer_size.height() / 2), thumb_rect);
  gfx::Rect scaled_thumb_rect = gfx::ScaleToEnclosingRect(thumb_rect, scale);

  {
    SCOPED_TRACE("No occlusion");
    gfx::Rect occluded;
    impl.AppendQuadsWithOcclusion(scrollbar_layer_impl, occluded);

    size_t partially_occluded_count = 0;
    VerifyQuadsAreOccluded(impl.quad_list(), occluded,
                           &partially_occluded_count);
    EXPECT_EQ(2u, impl.quad_list().size());
    EXPECT_EQ(0u, partially_occluded_count);

    // Note: this is also testing that the thumb and track are both
    // scaled by the internal contents scale.  It's not occlusion-related
    // but is easy to verify here.
    const viz::DrawQuad* thumb_draw_quad = impl.quad_list().ElementAt(0);
    const viz::DrawQuad* track_and_buttons_draw_quad =
        impl.quad_list().ElementAt(1);

    EXPECT_EQ(viz::DrawQuad::Material::kSolidColor, thumb_draw_quad->material);
    EXPECT_EQ(viz::DrawQuad::Material::kTextureContent,
              track_and_buttons_draw_quad->material);

    const viz::SolidColorDrawQuad* thumb_quad =
        viz::SolidColorDrawQuad::MaterialCast(thumb_draw_quad);
    const viz::TextureDrawQuad* track_and_buttons_quad =
        viz::TextureDrawQuad::MaterialCast(track_and_buttons_draw_quad);

    EXPECT_EQ(track_and_buttons_quad->rect, gfx::Rect(scaled_layer_size));
    EXPECT_EQ(scrollbar_layer_impl->contents_opaque(),
              track_and_buttons_quad->shared_quad_state->are_contents_opaque);
    EXPECT_EQ(track_and_buttons_quad->visible_rect,
              gfx::Rect(scaled_layer_size));
    EXPECT_FALSE(track_and_buttons_quad->needs_blending);
    EXPECT_EQ(thumb_quad->rect, scaled_thumb_rect);
    EXPECT_EQ(thumb_quad->visible_rect, scaled_thumb_rect);
    EXPECT_FALSE(thumb_quad->needs_blending);
    EXPECT_FALSE(thumb_quad->shared_quad_state->are_contents_opaque);

    EXPECT_EQ(1.f, thumb_quad->shared_quad_state->opacity);
    EXPECT_EQ(1.f, track_and_buttons_quad->shared_quad_state->opacity);
  }

  {
    SCOPED_TRACE("Full occlusion");
    gfx::Rect occluded(scrollbar_layer_impl->visible_layer_rect());
    impl.AppendQuadsWithOcclusion(scrollbar_layer_impl, occluded);

    VerifyQuadsExactlyCoverRect(impl.quad_list(), gfx::Rect());
    EXPECT_EQ(impl.quad_list().size(), 0u);
  }

  {
    SCOPED_TRACE("Partial occlusion");
    gfx::Rect occluded(0, 0, 5, 1000);
    impl.AppendQuadsWithOcclusion(scrollbar_layer_impl, occluded);

    size_t partially_occluded_count = 0;
    VerifyQuadsAreOccluded(impl.quad_list(), occluded,
                           &partially_occluded_count);
    // The layer outputs two quads, which is partially occluded.
    EXPECT_EQ(2u, impl.quad_list().size());
    EXPECT_EQ(2u, partially_occluded_count);
  }
}

TEST(PaintedScrollbarLayerImplTest,
     SolidColorThumbNinePatchTrackUnderClipAndScale) {
  gfx::Size layer_size(15, 1000);
  gfx::Rect clip_rect(0, 0, 1000, 1000);
  float scale = 33.f;
  gfx::Size scaled_layer_size = gfx::ScaleToCeiledSize(layer_size, scale);
  gfx::Size viewport_size(1000, 1000);

  LayerTreeImplTestBase impl;

  SkBitmap thumb_sk_bitmap;
  thumb_sk_bitmap.allocN32Pixels(10, 10);
  thumb_sk_bitmap.setImmutable();
  UIResourceId thumb_uid = 5;
  UIResourceBitmap thumb_bitmap(thumb_sk_bitmap);
  impl.host_impl()->CreateUIResource(thumb_uid, thumb_bitmap);

  SkBitmap track_and_buttons_sk_bitmap;
  track_and_buttons_sk_bitmap.allocN32Pixels(10, 10);
  track_and_buttons_sk_bitmap.setImmutable();
  UIResourceId track_and_buttons_uid = 6;
  UIResourceBitmap track_and_buttons_bitmap(track_and_buttons_sk_bitmap);
  impl.host_impl()->CreateUIResource(track_and_buttons_uid,
                                     track_and_buttons_bitmap);

  ScrollbarOrientation orientation = ScrollbarOrientation::kVertical;

  PaintedScrollbarLayerImpl* scrollbar_layer_impl =
      impl.AddLayerInActiveTree<PaintedScrollbarLayerImpl>(orientation, false,
                                                           false);
  scrollbar_layer_impl->SetBounds(layer_size);
  scrollbar_layer_impl->SetContentsOpaque(true);
  scrollbar_layer_impl->set_internal_contents_scale_and_bounds(
      scale, scaled_layer_size);
  scrollbar_layer_impl->SetDrawsContent(true);
  scrollbar_layer_impl->SetThumbThickness(11);
  scrollbar_layer_impl->SetThumbLength(500);
  scrollbar_layer_impl->SetTrackRect(gfx::Rect(0, 0, 15, layer_size.height()));
  scrollbar_layer_impl->SetCurrentPos(100.f / 4);
  scrollbar_layer_impl->SetClipLayerLength(100.f);
  scrollbar_layer_impl->SetScrollLayerLength(200.f);
  scrollbar_layer_impl->set_track_and_buttons_ui_resource_id(
      track_and_buttons_uid);
  scrollbar_layer_impl->SetThumbColor(SkColors::kRed);

  CopyProperties(impl.root_layer(), scrollbar_layer_impl);
  CreateClipNode(scrollbar_layer_impl).clip = gfx::RectF(clip_rect);
  CreateTransformNode(scrollbar_layer_impl).local.Scale(scale);

  impl.CalcDrawProps(viewport_size);

  gfx::Rect thumb_rect = scrollbar_layer_impl->ComputeThumbQuadRect();
  EXPECT_EQ(gfx::Rect(2, 500 / 4, 11, layer_size.height() / 2), thumb_rect);
  gfx::Rect scaled_thumb_rect = gfx::ScaleToEnclosingRect(thumb_rect, scale);

  impl.AppendQuads(scrollbar_layer_impl);
  EXPECT_EQ(2u, impl.quad_list().size());

  const viz::SolidColorDrawQuad* thumb_quad =
      viz::SolidColorDrawQuad::MaterialCast(impl.quad_list().ElementAt(0));
  EXPECT_EQ(thumb_quad->rect, scaled_thumb_rect);
  EXPECT_EQ(thumb_quad->visible_rect, scaled_thumb_rect);
  EXPECT_FALSE(thumb_quad->needs_blending);
  EXPECT_FALSE(thumb_quad->shared_quad_state->are_contents_opaque);
  EXPECT_EQ(1.f, thumb_quad->shared_quad_state->opacity);

  const viz::TextureDrawQuad* track_and_buttons_quad =
      viz::TextureDrawQuad::MaterialCast(impl.quad_list().ElementAt(1));
  EXPECT_EQ(track_and_buttons_quad->shared_quad_state->clip_rect, clip_rect);
  EXPECT_EQ(track_and_buttons_quad->rect, gfx::Rect(scaled_layer_size));
  EXPECT_EQ(scrollbar_layer_impl->contents_opaque(),
            track_and_buttons_quad->shared_quad_state->are_contents_opaque);
  EXPECT_EQ(track_and_buttons_quad->visible_rect, gfx::Rect(scaled_layer_size));
  EXPECT_FALSE(track_and_buttons_quad->needs_blending);
  EXPECT_EQ(track_and_buttons_quad->shared_quad_state->clip_rect, clip_rect);
  EXPECT_EQ(1.f, track_and_buttons_quad->shared_quad_state->opacity);
}

TEST(PaintedScrollbarLayerImplTest, PaintedOpacityChangesInvalidate) {
  LayerTreeImplTestBase impl;
  ScrollbarOrientation orientation = ScrollbarOrientation::kVertical;
  PaintedScrollbarLayerImpl* scrollbar_layer_impl =
      impl.AddLayerInActiveTree<PaintedScrollbarLayerImpl>(orientation, false,
                                                           false);
  EXPECT_FALSE(
      scrollbar_layer_impl->LayerPropertyChangedNotFromPropertyTrees());
  scrollbar_layer_impl->SetScrollbarPaintedOpacity(0.3f);
  EXPECT_TRUE(scrollbar_layer_impl->LayerPropertyChangedNotFromPropertyTrees());
}

class PaintedScrollbarLayerImplSolidColorThumbTest : public ::testing::Test {
 protected:
  void SetUp() override {
    impl_ = std::make_unique<LayerTreeImplTestBase>(LayerTreeSettings());
  }

  PaintedScrollbarLayerImpl* SetUpScrollbarLayerImpl(
      ScrollbarOrientation orientation,
      bool is_left_side_vertical_scrollbar,
      const gfx::Rect& track_rect,
      int thumb_thickness,
      int thumb_length,
      bool is_overlay = false) {
    PaintedScrollbarLayerImpl* scrollbar_layer_impl =
        impl_->AddLayerInActiveTree<PaintedScrollbarLayerImpl>(
            orientation, is_left_side_vertical_scrollbar, is_overlay);
    scrollbar_layer_impl->SetTrackRect(track_rect);
    scrollbar_layer_impl->SetThumbThickness(thumb_thickness);
    scrollbar_layer_impl->SetThumbLength(thumb_length);
    scrollbar_layer_impl->SetBounds(track_rect.size());
    scrollbar_layer_impl->SetThumbColor(SkColors::kRed);
    return scrollbar_layer_impl;
  }

  std::unique_ptr<LayerTreeImplTestBase> impl_;
};

TEST_F(PaintedScrollbarLayerImplSolidColorThumbTest, ComputeThumbQuadRect) {
  const PaintedScrollbarLayerImpl* scrollbar_layer_impl_vertical =
      SetUpScrollbarLayerImpl(ScrollbarOrientation::kVertical, false,
                              gfx::Rect(0, 0, 14, 100), 6, 30);
  EXPECT_EQ(scrollbar_layer_impl_vertical->ComputeThumbQuadRect(),
            gfx::Rect(4, 0, 6, 30));

  PaintedScrollbarLayerImpl* scrollbar_layer_impl_vertical_left =
      SetUpScrollbarLayerImpl(ScrollbarOrientation::kVertical, true,
                              gfx::Rect(0, 0, 14, 100), 6, 30);
  scrollbar_layer_impl_vertical_left->SetBounds(gfx::Size(14, 100));
  EXPECT_EQ(scrollbar_layer_impl_vertical_left->ComputeThumbQuadRect(),
            gfx::Rect(4, 0, 6, 30));

  const PaintedScrollbarLayerImpl* scrollbar_layer_impl_horizontal =
      SetUpScrollbarLayerImpl(ScrollbarOrientation::kHorizontal, false,
                              gfx::Rect(0, 0, 100, 14), 6, 30);
  EXPECT_EQ(scrollbar_layer_impl_horizontal->ComputeThumbQuadRect(),
            gfx::Rect(0, 4, 30, 6));
}

TEST_F(PaintedScrollbarLayerImplSolidColorThumbTest,
       ComputeHitTestableThumbQuadRect) {
  const PaintedScrollbarLayerImpl* scrollbar_layer_impl_vertical =
      SetUpScrollbarLayerImpl(ScrollbarOrientation::kVertical, false,
                              gfx::Rect(0, 0, 14, 100), 6, 30);
  EXPECT_EQ(scrollbar_layer_impl_vertical->ComputeHitTestableThumbQuadRect(),
            gfx::Rect(0, 0, 14, 30));

  PaintedScrollbarLayerImpl* scrollbar_layer_impl_vertical_left =
      SetUpScrollbarLayerImpl(ScrollbarOrientation::kVertical, true,
                              gfx::Rect(0, 0, 14, 100), 6, 30);
  scrollbar_layer_impl_vertical_left->SetBounds(gfx::Size(14, 100));
  EXPECT_EQ(
      scrollbar_layer_impl_vertical_left->ComputeHitTestableThumbQuadRect(),
      gfx::Rect(0, 0, 14, 30));

  const PaintedScrollbarLayerImpl* scrollbar_layer_impl_horizontal =
      SetUpScrollbarLayerImpl(ScrollbarOrientation::kHorizontal, false,
                              gfx::Rect(0, 0, 100, 14), 6, 30);
  EXPECT_EQ(scrollbar_layer_impl_horizontal->ComputeHitTestableThumbQuadRect(),
            gfx::Rect(0, 0, 30, 14));
}

class PaintedScrollbarLayerImplFluentOverlayTest
    : public PaintedScrollbarLayerImplSolidColorThumbTest {
 protected:
  void SetUp() override {
    LayerTreeSettings settings = CommitToPendingTreeLayerListSettings();
    settings.enable_fluent_overlay_scrollbar = true;
    settings.enable_fluent_scrollbar = true;
    impl_ = std::make_unique<LayerTreeImplTestBase>(settings);
  }
};

// Since the thumb's drawn thickness is smaller than the track's thickness,
// verify that the computed thickness is the width of the track. This prevents
// cases where clicking on the margin of the thumb would cause the thumb to not
// consider itself clicked/captured.
TEST_F(PaintedScrollbarLayerImplFluentOverlayTest,
       OverlayFluentThumbHasNoMargin) {
  {
    const PaintedScrollbarLayerImpl* scrollbar_layer_impl =
        SetUpScrollbarLayerImpl(ScrollbarOrientation::kVertical,
                                /*is_left_side_vertical_scrollbar=*/false,
                                gfx::Rect(0, 0, 14, 100), 6, 30,
                                /*is_overlay=*/true);
    gfx::Rect thumb =
        scrollbar_layer_impl->ComputeHitTestableExpandedThumbQuadRect();
    EXPECT_EQ(scrollbar_layer_impl->bounds().width(), thumb.width());
  }
  {
    const PaintedScrollbarLayerImpl* scrollbar_layer_impl =
        SetUpScrollbarLayerImpl(ScrollbarOrientation::kHorizontal,
                                /*is_left_side_vertical_scrollbar=*/false,
                                gfx::Rect(0, 0, 100, 14), 6, 30,
                                /*is_overlay=*/true);
    gfx::Rect thumb =
        scrollbar_layer_impl->ComputeHitTestableExpandedThumbQuadRect();
    EXPECT_EQ(scrollbar_layer_impl->bounds().height(), thumb.height());
  }
}

// Test that when no ThumbColor is set with Fluent Scrollbars enabled,
// AppendThumbQuads makes an early return and doesn't append any quads.
TEST_F(PaintedScrollbarLayerImplFluentOverlayTest,
       NoThumbColorDoesntAppendQuads) {
  PaintedScrollbarLayerImpl* scrollbar_layer_impl =
      impl_->AddLayerInActiveTree<PaintedScrollbarLayerImpl>(
          ScrollbarOrientation::kVertical,
          /*is_left_side_vertical_scrollbar=*/false, /*is_overlay=*/true);
  // Set all the correct dimensions required for quads to be appended.
  const gfx::Rect track_rect(0, 0, 14, 100);
  scrollbar_layer_impl->SetTrackRect(track_rect);
  scrollbar_layer_impl->SetThumbThickness(/*thumb_thickness=*/6);
  scrollbar_layer_impl->SetThumbLength(/*thumb_length=*/30);
  scrollbar_layer_impl->SetBounds(track_rect.size());

  // Ensure that no track quad will be appended by setting the thickness to
  // the minimum.
  scrollbar_layer_impl->SetThumbThickness(
      scrollbar_layer_impl->GetIdleThicknessScale());

  CopyProperties(impl_->root_layer(), scrollbar_layer_impl);
  impl_->CalcDrawProps(gfx::Size(500, 500));

  // AppendThumbQuads should return early after checking that there is no
  // `thumb_color_` and Fluent scrollbars are enabled.
  // AppendTrackQuads should return early when the Fluent overlay code decides
  // it shouldn't append a track quad.
  impl_->AppendQuads(scrollbar_layer_impl);
  EXPECT_TRUE(impl_->quad_list().empty());
}

}  // namespace
}  // namespace cc