Background filters are affected by masks

cc/trees/layer_tree_host_pixeltest_masks.cc

Index: cc/trees/layer_tree_host_pixeltest_masks.cc
diff --git a/cc/trees/layer_tree_host_pixeltest_masks.cc b/cc/trees/layer_tree_host_pixeltest_masks.cc
index eecc5a0e3eddc68ea43530e3359c64e3f1705bf0..a560d5e6ff512e1eae7b1fef3a7b7a34b56c1359 100644
--- a/cc/trees/layer_tree_host_pixeltest_masks.cc
+++ b/cc/trees/layer_tree_host_pixeltest_masks.cc
@@ -282,6 +282,114 @@ TEST_P(LayerTreeHostMasksPixelTest, MaskOfReplicaOfClippedLayer) {
 
 #endif  // !defined(OS_WIN)
 
+class CheckerContentLayerClient : public ContentLayerClient {
+ public:
+  explicit CheckerContentLayerClient(const gfx::Size& bounds)
+      : bounds_(bounds) {}
+  ~CheckerContentLayerClient() override {}
+  bool FillsBoundsCompletely() const override { return false; }
+  void PaintContents(SkCanvas* canvas,
+                     const gfx::Rect& rect,
+                     PaintingControlSetting picture_control) override {
+    SkPaint paint;
+    paint.setStyle(SkPaint::kStroke_Style);
+    paint.setStrokeWidth(SkIntToScalar(3));
+    paint.setColor(SK_ColorGREEN);
+    canvas->clear(SK_ColorTRANSPARENT);
+    for (int i = 0; i < bounds_.width(); i += 11) {
+      canvas->drawLine(i, 0, i, bounds_.height(), paint);
+    }
+  }
+  scoped_refptr<DisplayItemList> PaintContentsToDisplayList(
+      const gfx::Rect& clip,
+      PaintingControlSetting picture_control) override {
+    NOTIMPLEMENTED();
+    return DisplayItemList::Create();
+  }
+
+ private:
+  gfx::Size bounds_;
+};
+
+class CircleContentLayerClient : public ContentLayerClient {
+ public:
+  explicit CircleContentLayerClient(const gfx::Size& bounds)
+      : bounds_(bounds) {}
+  ~CircleContentLayerClient() override {}
+  bool FillsBoundsCompletely() const override { return false; }
+  void PaintContents(SkCanvas* canvas,
+                     const gfx::Rect& rect,
+                     PaintingControlSetting picture_control) override {
+    SkPaint paint;
+    paint.setStyle(SkPaint::kFill_Style);
+    paint.setColor(SK_ColorWHITE);
+    canvas->clear(SK_ColorTRANSPARENT);
+    canvas->drawCircle(bounds_.width() / 2,
+                       bounds_.height() / 2,
+                       bounds_.width() / 4,
+                       paint);
+  }
+  scoped_refptr<DisplayItemList> PaintContentsToDisplayList(
+      const gfx::Rect& clip,
+      PaintingControlSetting picture_control) override {
+    NOTIMPLEMENTED();
+    return DisplayItemList::Create();
+  }
+
+ private:
+  gfx::Size bounds_;
+};
+
+using LayerTreeHostMasksForBackgroundFiltersPixelTest =
+    ParameterizedPixelResourceTest;
+
+INSTANTIATE_TEST_CASE_P(
+    PixelResourceTest,
+    LayerTreeHostMasksForBackgroundFiltersPixelTest,
+    ::testing::Values(
+        // SOFTWARE, Background filters aren't implemented in software
+        // GL_GPU_RASTER_2D_DRAW, Gpu rasterisation has errors in accuracy
+        GL_ONE_COPY_2D_STAGING_2D_DRAW,
+        GL_ONE_COPY_RECT_STAGING_2D_DRAW,
+        GL_ONE_COPY_EXTERNAL_STAGING_2D_DRAW,
+        GL_ZERO_COPY_2D_DRAW,
+        GL_ZERO_COPY_RECT_DRAW,
+        GL_ZERO_COPY_EXTERNAL_DRAW,
+        GL_ASYNC_UPLOAD_2D_DRAW));
+
+TEST_P(LayerTreeHostMasksForBackgroundFiltersPixelTest,
+       MaskOfLayerWithBackgroundFilter) {
+  scoped_refptr<SolidColorLayer> background = CreateSolidColorLayer(
+      gfx::Rect(200, 200), SK_ColorWHITE);
+
+  gfx::Size picture_bounds(200, 200);
+  CheckerContentLayerClient picture_client(picture_bounds);
+  scoped_refptr<PictureLayer> picture = PictureLayer::Create(&picture_client);
+  picture->SetBounds(picture_bounds);
+  picture->SetIsDrawable(true);
+
+  scoped_refptr<SolidColorLayer> blur = CreateSolidColorLayer(
+      gfx::Rect(200, 200), SK_ColorTRANSPARENT);
+  background->AddChild(picture);
+  background->AddChild(blur);
+
+  FilterOperations filters;
+  filters.Append(FilterOperation::CreateBlurFilter(2.f));
+  blur->SetBackgroundFilters(filters);
+
+  gfx::Size mask_bounds(200, 200);
+  CircleContentLayerClient mask_client(mask_bounds);
+  scoped_refptr<PictureLayer> mask = PictureLayer::Create(&mask_client);
+  mask->SetBounds(mask_bounds);
+  mask->SetIsDrawable(true);
+  mask->SetIsMask(true);
+  blur->SetMaskLayer(mask.get());
+
+  RunPixelResourceTest(background,
+                       base::FilePath(
+                           FILE_PATH_LITERAL("mask_of_background_filter.png")));
+}
+
 }  // namespace
 }  // namespace cc