Add "threaded scrolling disabled" main thread scrolling reason [spv2]

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

 // Copyright 2015 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/LayoutTestHelper.h"
 #include "core/layout/LayoutTreeAsText.h"
 #include "core/layout/api/LayoutViewItem.h"
 #include "core/paint/ObjectPaintProperties.h"
 #include "core/paint/PaintPropertyTreePrinter.h"
 #include "platform/graphics/paint/GeometryMapper.h"
@@ skipping 1991 matching lines @@
 TEST_P(PaintPropertyTreeBuilderTest, SVGRootNoClip)
 {
     setBodyInnerHTML(
         "<svg id='svg' xmlns='http://www.w3.org/2000/svg' width='100px' height='100px' style='overflow: visible'>"
         "  <rect width='200' height='200' fill='red' />"
         "</svg>");
 
     EXPECT_FALSE(getLayoutObjectByElementId("svg")->objectPaintProperties()->overflowClip());
 }
 
+TEST_P(PaintPropertyTreeBuilderTest, ThreadedScrollingDisabledMainThreadScrollReason)
+{
+    setBodyInnerHTML(
+        "<style>"
+        "  #overflowA {"
+        "    position: absolute;"
+        "    overflow: scroll;"
+        "    width: 20px;"
+        "    height: 20px;"
+        "  }"
+        "  .forceScroll {"
+        "    height: 4000px;"
+        "  }"
+        "</style>"
+        "<div id='overflowA'>"
+        "  <div class='forceScroll'></div>"
+        "</div>"
+        "<div class='forceScroll'></div>");
+    Element* overflowA = document().getElementById("overflowA");
+    EXPECT_FALSE(frameScroll()->hasMainThreadScrollingReasons(MainThreadScrollingReason::kThreadedScrollingDisabled));
+    EXPECT_FALSE(overflowA->layoutObject()->objectPaintProperties()->scroll()->hasMainThreadScrollingReasons(MainThreadScrollingReason::kThreadedScrollingDisabled));
+
+    document().settings()->setThreadedScrollingEnabled(false);
+    document().view()->updateAllLifecyclePhases();
+
+    EXPECT_TRUE(frameScroll()->hasMainThreadScrollingReasons(MainThreadScrollingReason::kThreadedScrollingDisabled));
+    EXPECT_TRUE(overflowA->layoutObject()->objectPaintProperties()->scroll()->hasMainThreadScrollingReasons(MainThreadScrollingReason::kThreadedScrollingDisabled));
+}
+
 TEST_P(PaintPropertyTreeBuilderTest, MainThreadScrollReasonsWithNestedScrollers)
 {
     setBodyInnerHTML(
         "<style>"
         "  #overflowA {"
         "    position: absolute;"
         "    overflow: scroll;"
         "    width: 20px;"
         "    height: 20px;"
         "  }"
@@ skipping 80 matching lines @@
 
     // Removing a main thread scrolling reason should update the entire tree.
     overflowB->removeAttribute("class");
     document().view()->updateAllLifecyclePhases();
     EXPECT_FALSE(rootScroll()->hasMainThreadScrollingReasons(MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects));
     EXPECT_FALSE(overflowA->layoutObject()->objectPaintProperties()->scroll()->hasMainThreadScrollingReasons(MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects));
     EXPECT_FALSE(overflowB->layoutObject()->objectPaintProperties()->scroll()->hasMainThreadScrollingReasons(MainThreadScrollingReason::kHasBackgroundAttachmentFixedObjects));
 }
 
 } // namespace blink