Fix position of floating layer whose containing block is also floating

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 631 matching lines @@
   EXPECT_EQ(span, floating->parent());
   EXPECT_EQ(span, floating->containingLayer());
 
   EXPECT_EQ(LayoutPoint(83, 83), floating->location());
   EXPECT_EQ(LayoutPoint(100, 100), span->location());
   EXPECT_EQ(LayoutPoint(83, 83), floating->visualOffsetFromAncestor(span));
   EXPECT_EQ(LayoutPoint(183, 183), floating->visualOffsetFromAncestor(
                                        document().layoutView()->layer()));
 }
 
+TEST_P(PaintLayerTest, FloatLayerUnderFloatUnderInlineLayer) {
+  setBodyInnerHTML(
+      "<style>body {margin: 0}</style>"
+      "<span id='span' style='position: relative; top: 100px; left: 100px'>"
+      "  <div style='float: left; margin: 33px'>"
+      "    <div id='floating'"
+      "        style='float: left; position: relative; top: 50px; left: 50px'>"
+      "    </div>"
+      "  </div>"
+      "</span>");
+
+  PaintLayer* floating =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("floating"))->layer();
+  PaintLayer* span =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("span"))->layer();
+
+  EXPECT_EQ(span, floating->parent());
+  EXPECT_EQ(span->parent(), floating->containingLayer());
+
+  EXPECT_EQ(LayoutPoint(83, 83), floating->location());
+  EXPECT_EQ(LayoutPoint(100, 100), span->location());
+  EXPECT_EQ(LayoutPoint(-17, -17), floating->visualOffsetFromAncestor(span));
+  EXPECT_EQ(LayoutPoint(83, 83), floating->visualOffsetFromAncestor(
+                                     document().layoutView()->layer()));
+}
+
+TEST_P(PaintLayerTest, FloatLayerUnderFloatLayerUnderInlineLayer) {
+  setBodyInnerHTML(
+      "<style>body {margin: 0}</style>"
+      "<span id='span' style='position: relative; top: 100px; left: 100px'>"
+      "  <div id='floatingParent'"
+      "      style='float: left; position: relative; margin: 33px'>"
+      "    <div id='floating'"
+      "        style='float: left; position: relative; top: 50px; left: 50px'>"
+      "    </div>"
+      "  </div>"
+      "</span>");
+
+  PaintLayer* floating =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("floating"))->layer();
+  PaintLayer* floatingParent =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("floatingParent"))
+          ->layer();
+  PaintLayer* span =
+      toLayoutBoxModelObject(getLayoutObjectByElementId("span"))->layer();
+
+  EXPECT_EQ(floatingParent, floating->parent());
+  EXPECT_EQ(floatingParent, floating->containingLayer());
+  EXPECT_EQ(span, floatingParent->parent());
+  EXPECT_EQ(span->parent(), floatingParent->containingLayer());
+
+  EXPECT_EQ(LayoutPoint(50, 50), floating->location());
+  EXPECT_EQ(LayoutPoint(33, 33), floatingParent->location());
+  EXPECT_EQ(LayoutPoint(100, 100), span->location());
+  EXPECT_EQ(LayoutPoint(-17, -17), floating->visualOffsetFromAncestor(span));
+  EXPECT_EQ(LayoutPoint(-67, -67),
+            floatingParent->visualOffsetFromAncestor(span));
+  EXPECT_EQ(LayoutPoint(83, 83), floating->visualOffsetFromAncestor(
+                                     document().layoutView()->layer()));
+}
+
 TEST_P(PaintLayerTest, CompositingContainerFloatingIframe) {
   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)'>"
       "      <iframe srcdoc='foo' id='target' style='float: right'></iframe>"
@@ skipping 75 matching lines @@
   EXPECT_EQ(LayoutPoint(-150, 50), spanner->location());
   EXPECT_EQ(LayoutPoint(100, 100), extraLayer->location());
   // -60 = 2nd-column-x(40) - scroll-offset-x(200) + x-location(100)
   // 20 = y-location(100) - column-height(80)
   EXPECT_EQ(LayoutPoint(-60, 20),
             extraLayer->visualOffsetFromAncestor(columns));
   EXPECT_EQ(LayoutPoint(-150, 50), spanner->visualOffsetFromAncestor(columns));
 }
 
 }  // namespace blink