Move computation of 3D descendants to the descendant-dependent flags walk.

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/html/HTMLIFrameElement.h"
 #include "core/layout/LayoutBoxModelObject.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "core/layout/LayoutView.h"
@@ skipping 272 matching lines @@
   PaintLayer* visible =
       toLayoutBoxModelObject(getLayoutObjectByElementId("visible"))->layer();
 
   EXPECT_TRUE(invisible->hasVisibleDescendant());
   EXPECT_FALSE(visible->hasVisibleDescendant());
 
   EXPECT_FALSE(invisible->hasNonIsolatedDescendantWithBlendMode());
   EXPECT_FALSE(invisible->hasDescendantWithClipPath());
 }
 
+TEST_P(PaintLayerTest, Has3DTransformedDescendant) {
+  enableCompositing();
+  setBodyInnerHTML(
+      "<div id='parent' style='position:relative; z-index: 0'>"
+      "  <div id='child' style='transform: translateZ(1px)'>"
+      "  </div>"
+      "</div>");
+  PaintLayer* parent =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("parent"))->layer();
+  PaintLayer* child =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("child"))->layer();
+
+  EXPECT_TRUE(parent->has3DTransformedDescendant());
+  EXPECT_FALSE(child->has3DTransformedDescendant());
+}
+
+TEST_P(PaintLayerTest, Has3DTransformedDescendantChangeStyle) {
+  enableCompositing();
+  setBodyInnerHTML(
+      "<div id='parent' style='position:relative; z-index: 0'>"
+      "  <div id='child' style='position:relative '>"
+      "  </div>"
+      "</div>");
+  PaintLayer* parent =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("parent"))->layer();
+  PaintLayer* child =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("child"))->layer();
+
+  EXPECT_FALSE(parent->has3DTransformedDescendant());
+  EXPECT_FALSE(child->has3DTransformedDescendant());
+
+  document().getElementById("child")->setAttribute(
+      HTMLNames::styleAttr, "transform: translateZ(1px)");
+  document().view()->updateAllLifecyclePhases();
+
+  EXPECT_TRUE(parent->has3DTransformedDescendant());
+  EXPECT_FALSE(child->has3DTransformedDescendant());
+}
+
+TEST_P(PaintLayerTest, Has3DTransformedDescendantNotStacking) {
+  enableCompositing();
+  setBodyInnerHTML(
+      "<div id='parent' style='position:relative;'>"
+      "  <div id='child' style='transform: translateZ(1px)'>"
+      "  </div>"
+      "</div>");
+  PaintLayer* parent =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("parent"))->layer();
+  PaintLayer* child =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("child"))->layer();
+
+  // |child| is not a stacking child of |parent|, so it has no 3D transformed
+  // descendant.
+  EXPECT_FALSE(parent->has3DTransformedDescendant());
+  EXPECT_FALSE(child->has3DTransformedDescendant());
+}
+
+TEST_P(PaintLayerTest, Has3DTransformedGrandchildWithPreserve3d) {
+  enableCompositing();
+  setBodyInnerHTML(
+      "<div id='parent' style='position:relative; z-index: 0'>"
+      "  <div id='child' style='transform-style: preserve-3d'>"
+      "    <div id='grandchild' style='transform: translateZ(1px)'>"
+      "    </div>"
+      "  </div>"
+      "</div>");
+  PaintLayer* parent =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("parent"))->layer();
+  PaintLayer* child =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("child"))->layer();
+  PaintLayer* grandchild =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("grandchild"))->layer();
+
+  EXPECT_TRUE(parent->has3DTransformedDescendant());
+  EXPECT_TRUE(child->has3DTransformedDescendant());
+  EXPECT_FALSE(grandchild->has3DTransformedDescendant());
+}
+
 TEST_P(PaintLayerTest, DescendantDependentFlagsStopsAtThrottledFrames) {
   enableCompositing();
   setBodyInnerHTML(
       "<style>body { margin: 0; }</style>"
       "<div id='transform' style='transform: translate3d(4px, 5px, 6px);'>"
       "</div>"
       "<iframe id='iframe' sandbox></iframe>");
   setChildFrameHTML(
       "<style>body { margin: 0; }</style>"
       "<div id='iframeTransform'"
@@ skipping 91 matching lines @@
   EXPECT_EQ(LayoutRect(0, 30, 50, 5), content->visualRect());
 
   scroller->getScrollableArea()->setScrollOffset(ScrollOffset(0, 20),
                                                  ProgrammaticScroll);
   document().view()->updateAllLifecyclePhases();
   EXPECT_EQ(LayoutRect(0, 30, 50, 10), contentLayer->visualRect());
   EXPECT_EQ(LayoutRect(0, 30, 50, 5), content->visualRect());
 }
 
 }  // namespace blink