Replace adjustment of previous visual rects on scroll with normal paint invalidation

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 327 matching lines @@
   }
 
   document().view()->updateAllLifecyclePhases();
   EXPECT_FALSE(childDocument()
                    .view()
                    ->layoutView()
                    ->layer()
                    ->m_needsDescendantDependentFlagsUpdate);
 }
 
+TEST_P(PaintLayerTest, PaintInvalidationOnNonCompositedScroll) {
+  if (RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+    return;
+
+  setBodyInnerHTML(
+      "<style>* { margin: 0 } ::-webkit-scrollbar { display: none }</style>"
+      "<div id='scroller' style='overflow: scroll; width: 50px; height: 50px'>"
+      "  <div style='height: 400px'>"
+      "    <div id='content-layer' style='position: relative; height: 10px;"
+      "        top: 30px; background: blue'>"
+      "      <div id='content' style='height: 5px; background: yellow'></div>"
+      "    </div>"
+      "  </div>"
+      "</div>");
+
+  LayoutBox* scroller = toLayoutBox(getLayoutObjectByElementId("scroller"));
+  LayoutObject* contentLayer = getLayoutObjectByElementId("content-layer");
+  LayoutObject* content = getLayoutObjectByElementId("content");
+  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, 10, 50, 10), contentLayer->visualRect());
+  EXPECT_EQ(LayoutRect(0, 10, 50, 5), content->visualRect());
+}
+
+TEST_P(PaintLayerTest, PaintInvalidationOnCompositedScroll) {
+  enableCompositing();
+  setBodyInnerHTML(
+      "<style>* { margin: 0 } ::-webkit-scrollbar { display: none }</style>"
+      "<div id='scroller' style='overflow: scroll; width: 50px; height: 50px;"
+      "    will-change: transform'>"
+      "  <div style='height: 400px'>"
+      "    <div id='content-layer' style='position: relative; height: 10px;"
+      "        top: 30px; background: blue'>"
+      "      <div id='content' style='height: 5px; background: yellow'></div>"
+      "    </div>"
+      "  </div>"
+      "</div>");
+
+  LayoutBox* scroller = toLayoutBox(getLayoutObjectByElementId("scroller"));
+  LayoutObject* contentLayer = getLayoutObjectByElementId("content-layer");
+  LayoutObject* content = getLayoutObjectByElementId("content");
+  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());
+}
+
 }  // namespace blink