Exclude border from overflow scroller in sticky constraints.

third_party/WebKit/Source/core/layout/LayoutBoxModelObjectTest.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/layout/LayoutBoxModelObject.h"
 
 #include "core/html/HTMLElement.h"
 #include "core/layout/ImageQualityController.h"
 #include "core/layout/LayoutTestHelper.h"
 #include "core/page/scrolling/StickyPositionScrollingConstraints.h"
@@ skipping 16 matching lines @@
   }
 };
 
 // Verifies that the sticky constraints are correctly computed.
 TEST_F(LayoutBoxModelObjectTest, StickyPositionConstraints) {
   setBodyInnerHTML(
       "<style>#sticky { position: sticky; top: 0; width: 100px; height: 100px; "
       "}"
       "#container { box-sizing: border-box; position: relative; top: 100px; "
       "height: 400px; width: 200px; padding: 10px; border: 5px solid black; }"
-      "#scroller { height: 100px; overflow: auto; position: relative; top: "
-      "200px; }"
+      "#scroller { width: 400px; height: 100px; overflow: auto; "
+      "position: relative; top: 200px; border: 2px solid black; }"
       ".spacer { height: 1000px; }</style>"
       "<div id='scroller'><div id='container'><div "
       "id='sticky'></div></div><div class='spacer'></div></div>");
   LayoutBoxModelObject* scroller =
       toLayoutBoxModelObject(getLayoutObjectByElementId("scroller"));
   PaintLayerScrollableArea* scrollableArea = scroller->getScrollableArea();
   scrollableArea->scrollToAbsolutePosition(
       FloatPoint(scrollableArea->scrollOffsetInt().width(), 50));
   ASSERT_EQ(50.0, scrollableArea->scrollPosition().y());
   LayoutBoxModelObject* sticky =
       toLayoutBoxModelObject(getLayoutObjectByElementId("sticky"));
   sticky->updateStickyPositionConstraints();
   ASSERT_EQ(scroller->layer(), sticky->layer()->ancestorOverflowLayer());
 
   const StickyPositionScrollingConstraints& constraints =
       scrollableArea->stickyConstraintsMap().get(sticky->layer());
   ASSERT_EQ(0.f, constraints.topOffset());
 
   // The coordinates of the constraint rects should all be with respect to the
   // unscrolled scroller.
   ASSERT_EQ(IntRect(15, 115, 170, 370),
             enclosingIntRect(
                 getScrollContainerRelativeContainingBlockRect(constraints)));
   ASSERT_EQ(
       IntRect(15, 115, 100, 100),
       enclosingIntRect(getScrollContainerRelativeStickyBoxRect(constraints)));
+
+  // The sticky constraining rect also doesn't include the border offset.

[chrishtr, 2016/11/12 00:17:20]

Please add a vertical-rl example also.

[flackr, 2016/11/14 14:50:14]

Done.

+  ASSERT_EQ(IntRect(0, 50, 400, 100),
+            enclosingIntRect(sticky->computeStickyConstrainingRect()));
 }
 
 // Verifies that the sticky constraints are not affected by transforms
 TEST_F(LayoutBoxModelObjectTest, StickyPositionTransforms) {
   setBodyInnerHTML(
       "<style>#sticky { position: sticky; top: 0; width: 100px; height: 100px; "
       "transform: scale(2); transform-origin: top left; }"
       "#container { box-sizing: border-box; position: relative; top: 100px; "
       "height: 400px; width: 200px; padding: 10px; border: 5px solid black; "
       "transform: scale(2); transform-origin: top left; }"
@@ skipping 62 matching lines @@
       enclosingIntRect(getScrollContainerRelativeStickyBoxRect(constraints)));
 }
 
 // Verifies that the sticky constraints are correct when the sticky position
 // container is also the ancestor scroller.
 TEST_F(LayoutBoxModelObjectTest, StickyPositionContainerIsScroller) {
   setBodyInnerHTML(
       "<style>#sticky { position: sticky; top: 0; width: 100px; height: 100px; "
       "}"
       "#scroller { height: 100px; width: 400px; overflow: auto; position: "
-      "relative; top: 200px; }"
+      "relative; top: 200px; border: 2px solid black; }"
       ".spacer { height: 1000px; }</style>"
       "<div id='scroller'><div id='sticky'></div><div "
       "class='spacer'></div></div>");
   LayoutBoxModelObject* scroller =
       toLayoutBoxModelObject(getLayoutObjectByElementId("scroller"));
   PaintLayerScrollableArea* scrollableArea = scroller->getScrollableArea();
   scrollableArea->scrollToAbsolutePosition(
       FloatPoint(scrollableArea->scrollPosition().x(), 50));
   ASSERT_EQ(50.0, scrollableArea->scrollPosition().y());
   LayoutBoxModelObject* sticky =
@@ skipping 39 matching lines @@
   const StickyPositionScrollingConstraints& constraints =
       scrollableArea->stickyConstraintsMap().get(sticky->layer());
   ASSERT_EQ(IntRect(15, 115, 170, 370),
             enclosingIntRect(
                 getScrollContainerRelativeContainingBlockRect(constraints)));
   ASSERT_EQ(
       IntRect(15, 165, 100, 100),
       enclosingIntRect(getScrollContainerRelativeStickyBoxRect(constraints)));
 }
 }  // namespace blink