Reland: Don't early out recursion into PaintLayerChildren when computing composited bounds.

third_party/WebKit/Source/core/paint/PaintLayerTest.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/PaintLayer.h"
 
 #include "core/layout/LayoutBoxModelObject.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "core/layout/LayoutView.h"
 
 namespace blink {
 
 using PaintLayerTest = RenderingTest;
 
+TEST_F(PaintLayerTest, CompositedBoundsAbsPosGrandchild) {
+  setBodyInnerHTML(
+      " <div id='parent'><div id='absposparent'><div id='absposchild'>"
+      " </div></div></div>"
+      "<style>"
+      "  #parent { position: absolute; z-index: 0; overflow: hidden;"
+      "  background: lightgray; width: 150px; height: 150px;"
+      "  will-change: transform; }"
+      "  #absposparent { position: absolute; z-index: 0; }"
+      "  #absposchild { position: absolute; top: 0px; left: 0px; height: 200px;"
+      "  width: 200px; background: lightblue; }</style>");
+
+  PaintLayer* parentLayer =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("parent"))->layer();
+  // Since "absposchild" is clipped by "parent", it should not expand the
+  // composited bounds for "parent" beyond its intrinsic size of 150x150.
+  EXPECT_EQ(LayoutRect(0, 0, 150, 150),
+            parentLayer->boundingBoxForCompositing());
+}
+
 TEST_F(PaintLayerTest, PaintingExtentReflection) {
   setBodyInnerHTML(
       "<div id='target' style='background-color: blue; position: absolute;"
       "    width: 110px; height: 120px; top: 40px; left: 60px;"
       "    -webkit-box-reflect: below 3px'>"
       "</div>");
 
   PaintLayer* layer =
       toLayoutBoxModelObject(getLayoutObjectByElementId("target"))->layer();
   EXPECT_EQ(
@@ skipping 61 matching lines @@
   scrollLayer->getScrollableArea()->setScrollOffset(ScrollOffset(1000, 1000),
                                                     ProgrammaticScroll);
   document().view()->updateAllLifecyclePhasesExceptPaint();
   EXPECT_EQ(LayoutPoint(-1000, -1000), contentLayer->location());
   EXPECT_TRUE(contentLayer->needsRepaint());
   EXPECT_TRUE(scrollLayer->needsRepaint());
   document().view()->updateAllLifecyclePhases();
 }
 
 }  // namespace blink