Clean compositing inputs for location APIs for sticky-affected elements.

third_party/WebKit/Source/core/paint/PaintLayerScrollableAreaTest.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayerScrollableAreaTest.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerScrollableAreaTest.cpp b/third_party/WebKit/Source/core/paint/PaintLayerScrollableAreaTest.cpp
index 106cd217ab03aece83fae61ebf2fb64346a08c80..1210864ae0e93d3a52f5cfe9cf38577ded7948e9 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableAreaTest.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableAreaTest.cpp
@@ -29,7 +29,7 @@ class MockChromeClient : public EmptyChromeClient {
   }
 };
 
-}  // namespace {
+}  // namespace
 
 class PaintLayerScrollableAreaTest : public RenderingTest {
  public:
@@ -628,4 +628,30 @@ TEST_F(PaintLayerScrollableAreaTest, FloatOverflowInRtlContainer) {
   ASSERT_TRUE(scrollable_area);
   EXPECT_FALSE(scrollable_area->HasHorizontalScrollbar());
 }
+
+TEST_F(PaintLayerScrollableAreaTest,
+       StickyPositionConstraintsInvalidatedByLayout) {
+  SetBodyInnerHTML(
+      "<style>#scroller { overflow-y: scroll; height: 100px; }"
+      "#sticky { height: 25px; position: sticky; top: 0; }"
+      "#padding { height: 500px; }</style>"
+      "<div id='scroller'><div id='sticky'></div><div id='padding'></div>"
+      "</div>");
+
+  LayoutBoxModelObject* scroller =
+      ToLayoutBoxModelObject(GetLayoutObjectByElementId("scroller"));
+  LayoutBoxModelObject* sticky =
+      ToLayoutBoxModelObject(GetLayoutObjectByElementId("sticky"));
+
+  EXPECT_FALSE(sticky->Layer()->NeedsCompositingInputsUpdate());
+
+  PaintLayerScrollableArea* scrollable_area = scroller->GetScrollableArea();
+  ASSERT_TRUE(scrollable_area);
+
+  // Fake layout.
+  scrollable_area->UpdateAfterLayout();
+
+  EXPECT_TRUE(sticky->Layer()->NeedsCompositingInputsUpdate());
+  EXPECT_EQ(0u, scrollable_area->GetStickyConstraintsMap().size());
+}
 }