[blink] Unify PaintLayerClipper behavior with kIgnoreOverflowClip

third_party/WebKit/Source/core/paint/PaintLayerClipperTest.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayerClipperTest.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerClipperTest.cpp b/third_party/WebKit/Source/core/paint/PaintLayerClipperTest.cpp
index 5d6d0ec152b6d3e9fa681cbbfa3e917a4e95a49f..20e0a27982c89dbc5f81124de48274d8ccf6afb2 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerClipperTest.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerClipperTest.cpp
@@ -512,4 +512,114 @@ TEST_P(PaintLayerClipperTest, Filter) {
   EXPECT_EQ(LayoutRect(0, 0, 100, 200), foreground_rect.Rect());
 }
 
+// Computed infinite clip rects may not match LayoutRect::InfiniteIntRect()
+// due to floating point errors.
+static bool IsInfinite(const LayoutRect& rect) {
+  return rect.X().Round() < -10000000 && rect.MaxX().Round() > 10000000
+      && rect.Y().Round() < -10000000 && rect.MaxY().Round() > 10000000;
+}
+
+TEST_P(PaintLayerClipperTest, IgnoreRootLayerClipWithCSSClip) {
+  SetBodyInnerHTML(
+      "<style>"
+      "  #root { "
+      "    width: 400px; height: 400px;"
+      "    position: absolute; clip: rect(0, 50px, 100px, 0);"
+      "  }"
+      "  #target {"
+      "    position: relative;"
+      "  }"
+      "</style>"
+      "<div id='root'>"
+      "  <div id='target'></div>"
+      "</div>");
+
+  PaintLayer* root =
+      ToLayoutBoxModelObject(GetLayoutObjectByElementId("root"))->Layer();
+  PaintLayer* target =
+      ToLayoutBoxModelObject(GetLayoutObjectByElementId("target"))->Layer();
+  ClipRectsContext context(root, kPaintingClipRectsIgnoringOverflowClip);
+  PaintLayer::GeometryMapperOption option = PaintLayer::kDoNotUseGeometryMapper;
+  if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled())
+    option = PaintLayer::kUseGeometryMapper;
+  LayoutRect infinite_rect(LayoutRect::InfiniteIntRect());
+  LayoutRect layer_bounds(infinite_rect);
+  ClipRect background_rect(infinite_rect);
+  ClipRect foreground_rect(infinite_rect);
+  target->Clipper(option).CalculateRects(context, infinite_rect, layer_bounds,
+                                         background_rect, foreground_rect);
+
+  EXPECT_TRUE(IsInfinite(background_rect.Rect()));
+  EXPECT_TRUE(IsInfinite(foreground_rect.Rect()));
+}
+
+TEST_P(PaintLayerClipperTest, IgnoreRootLayerClipWithOverflowClip) {
+  SetBodyInnerHTML(
+      "<style>"
+      "  #root { "
+      "    width: 400px; height: 400px;"
+      "    overflow: hidden;"
+      "  }"
+      "  #target {"
+      "    position: relative;"
+      "  }"
+      "</style>"
+      "<div id='root'>"
+      "  <div id='target'></div>"
+      "</div>");
+
+  PaintLayer* root =
+      ToLayoutBoxModelObject(GetLayoutObjectByElementId("root"))->Layer();
+  PaintLayer* target =
+      ToLayoutBoxModelObject(GetLayoutObjectByElementId("target"))->Layer();
+  ClipRectsContext context(root, kPaintingClipRectsIgnoringOverflowClip);
+  PaintLayer::GeometryMapperOption option = PaintLayer::kDoNotUseGeometryMapper;
+  if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled())
+    option = PaintLayer::kUseGeometryMapper;
+  LayoutRect infinite_rect(LayoutRect::InfiniteIntRect());
+  LayoutRect layer_bounds(infinite_rect);
+  ClipRect background_rect(infinite_rect);
+  ClipRect foreground_rect(infinite_rect);
+  target->Clipper(option).CalculateRects(context, infinite_rect, layer_bounds,
+                                         background_rect, foreground_rect);
+
+  EXPECT_TRUE(IsInfinite(background_rect.Rect()));
+  EXPECT_TRUE(IsInfinite(foreground_rect.Rect()));
+}
+
+TEST_P(PaintLayerClipperTest, IgnoreRootLayerClipWithBothClip) {
+  SetBodyInnerHTML(
+      "<style>"
+      "  #root { "
+      "    width: 400px; height: 400px;"
+      "    position: absolute; clip: rect(0, 50px, 100px, 0);"
+      "    overflow: hidden;"
+      "  }"
+      "  #target {"
+      "    position: relative;"
+      "  }"
+      "</style>"
+      "<div id='root'>"
+      "  <div id='target'></div>"
+      "</div>");
+
+  PaintLayer* root =
+      ToLayoutBoxModelObject(GetLayoutObjectByElementId("root"))->Layer();
+  PaintLayer* target =
+      ToLayoutBoxModelObject(GetLayoutObjectByElementId("target"))->Layer();
+  ClipRectsContext context(root, kPaintingClipRectsIgnoringOverflowClip);
+  PaintLayer::GeometryMapperOption option = PaintLayer::kDoNotUseGeometryMapper;
+  if (RuntimeEnabledFeatures::slimmingPaintInvalidationEnabled())
+    option = PaintLayer::kUseGeometryMapper;
+  LayoutRect infinite_rect(LayoutRect::InfiniteIntRect());
+  LayoutRect layer_bounds(infinite_rect);
+  ClipRect background_rect(infinite_rect);
+  ClipRect foreground_rect(infinite_rect);
+  target->Clipper(option).CalculateRects(context, infinite_rect, layer_bounds,
+                                         background_rect, foreground_rect);
+
+  EXPECT_TRUE(IsInfinite(background_rect.Rect()));
+  EXPECT_TRUE(IsInfinite(foreground_rect.Rect()));
+}
+
 }  // namespace blink