Disable scroll anchoring when in printing mode

third_party/WebKit/Source/core/layout/ScrollAnchorTest.cpp

Index: third_party/WebKit/Source/core/layout/ScrollAnchorTest.cpp
diff --git a/third_party/WebKit/Source/core/layout/ScrollAnchorTest.cpp b/third_party/WebKit/Source/core/layout/ScrollAnchorTest.cpp
index 60e58d7a6f792814e153818b217b46b0f6abb112..9586d14c85969996b3e39b97a83f433529731ea8 100644
--- a/third_party/WebKit/Source/core/layout/ScrollAnchorTest.cpp
+++ b/third_party/WebKit/Source/core/layout/ScrollAnchorTest.cpp
@@ -8,6 +8,7 @@
 #include "core/frame/VisualViewport.h"
 #include "core/layout/LayoutBox.h"
 #include "core/layout/LayoutTestHelper.h"
+#include "core/page/PrintContext.h"
 #include "core/paint/PaintLayerScrollableArea.h"
 #include "platform/testing/HistogramTester.h"
 
@@ -841,6 +842,24 @@ TEST_F(ScrollAnchorTest, NonDefaultRootScroller) {
   EXPECT_EQ(nullptr, scrollAnchor(layoutViewport()).anchorObject());
 }
 
+// This test verifies that scroll anchoring is disabled when the document is in
+// printing mode.
+TEST_F(ScrollAnchorTest, AnchoringDisabledForPrinting) {
+  setBodyInnerHTML(
+      "<style> body { height: 1000px } div { height: 100px } </style>"
+      "<div id='block1'>abc</div>"
+      "<div id='block2'>def</div>");
+
+  ScrollableArea* viewport = layoutViewport();
+  scrollLayoutViewport(ScrollOffset(0, 150));
+
+  // This will trigger printing and layout.
+  PrintContext::numberOfPages(document().frame(), FloatSize(500, 500));
+
+  EXPECT_EQ(150, viewport->scrollOffsetInt().height());
+  EXPECT_EQ(nullptr, scrollAnchor(viewport).anchorObject());
+}
+
 class ScrollAnchorCornerTest : public ScrollAnchorTest {
  protected:
   void checkCorner(Corner corner,