[blink] Unify PaintLayerClipper behavior with kIgnoreOverflowClip

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/PaintLayerClipper.h"
 
 #include "core/layout/LayoutBoxModelObject.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "core/layout/LayoutView.h"
 #include "core/paint/PaintLayer.h"
@@ skipping 494 matching lines @@
   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_EQ(LayoutRect(-12, -9, 124, 224), background_rect.Rect());
   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