Fix GraphicsLayerUpdater::UpdateContext::compositingContainer() for corner cases

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 498 matching lines @@
   EXPECT_EQ(LayoutRect(0, 30, 50, 10), contentLayer->visualRect());
   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());
 }
 
-TEST_P(PaintLayerTest, CompositingContainerFloat) {
+TEST_P(PaintLayerTest, CompositingContainerFloatUnderInline) {
   enableCompositing();
   setBodyInnerHTML(
       "<div id='compositedContainer' style='position: relative;"
       "    will-change: transform'>"
       "  <div id='containingBlock' style='position: relative; z-index: 0'>"
       "    <div style='backface-visibility: hidden'></div>"
       "    <span id='span'"
       "        style='clip-path: polygon(0px 15px, 0px 54px, 100px 0px)'>"
       "      <div id='target' style='float: right; position: relative'></div>"
       "    </span>"
@@ skipping 10 matching lines @@
           ->layer();
 
   // enclosingLayerWithCompositedLayerMapping is not needed or applicable to
   // SPv2.
   if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
     EXPECT_EQ(compositedContainer,
               target->enclosingLayerWithCompositedLayerMapping(ExcludeSelf));
   }
 }
 
+TEST_P(PaintLayerTest, CompositingContainerUnderFloatUnderInline) {

[Xianzhu, 2017/03/30 22:23:12]

This test also passes without any real code change.

+  enableCompositing();
+  setBodyInnerHTML(
+      "<div id='compositedContainer' style='position: relative;"
+      "    will-change: transform'>"
+      "  <div id='containingBlock' style='position: relative; z-index: 0'>"
+      "    <div style='backface-visibility: hidden'></div>"
+      "    <span id='span'"
+      "        style='clip-path: polygon(0px 15px, 0px 54px, 100px 0px)'>"
+      "      <div style='float: right'>"
+      "        <div id='target' style='position: relative'></div>"
+      "      </div>"
+      "    </span>"
+      "  </div>"
+      "</div>");
+
+  PaintLayer* target =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("target"))->layer();
+  PaintLayer* span =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("span"))->layer();
+  EXPECT_EQ(span, target->compositingContainer());
+  PaintLayer* compositedContainer =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("compositedContainer"))
+          ->layer();
+
+  // enclosingLayerWithCompositedLayerMapping is not needed or applicable to
+  // SPv2.
+  if (!RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
+    EXPECT_EQ(compositedContainer,
+              target->enclosingLayerWithCompositedLayerMapping(ExcludeSelf));
+  }
+}
+
 TEST_P(PaintLayerTest, FloatLayerAndAbsoluteUnderInlineLayer) {
   setBodyInnerHTML(
       "<div id='container' style='position: absolute; top: 20px; left: 20px'>"
       "  <div style='margin: 33px'>"
       "    <span id='span' style='position: relative; top: 100px; left: 100px'>"
       "      <div id='floating'"
       "        style='float: left; position: relative; top: 50px; left: 50px'>"
       "      </div>"
       "      <div id='absolute'"
       "        style='position: absolute; top: 50px; left: 50px'>"
@@ skipping 282 matching lines @@
   RefPtr<ComputedStyle> oldStyle =
       ComputedStyle::clone(targetObject->styleRef());
   ComputedStyle* newStyle = targetObject->mutableStyle();
   newStyle->setHasCurrentTransformAnimation();
   targetPaintLayer->updateTransform(oldStyle.get(), *newStyle);
 
   EXPECT_NE(nullptr, targetPaintLayer->transform());
 }
 
 }  // namespace blink