Don't adjust for scrolling of the ancestor, rather than un-adjusting for it later.

third_party/WebKit/Source/core/layout/VisualRectMappingTest.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/LayoutView.h"
 #include "core/layout/PaintInvalidationState.h"
 #include "core/paint/PaintLayer.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 42 matching lines @@
         "  text text text text text text text"
         "</div>");
 
     LayoutBlock* container = toLayoutBlock(getLayoutObjectByElementId("container"));
     LayoutText* text = toLayoutText(container->lastChild());
 
     container->setScrollTop(LayoutUnit(50));
     LayoutRect originalRect(0, 60, 20, 80);
     LayoutRect rect = originalRect;
     EXPECT_TRUE(text->mapToVisualRectInAncestorSpace(container, rect));
+    rect.move(-container->scrolledContentOffset());
     EXPECT_EQ(rect, LayoutRect(0, 10, 20, 80));
 
     rect = originalRect;
     EXPECT_TRUE(text->mapToVisualRectInAncestorSpace(&layoutView(), rect));
     EXPECT_EQ(rect, LayoutRect(0, 10, 20, 40));
     checkPaintInvalidationStateRectMapping(rect, originalRect, *text, layoutView(), layoutView());
 
     rect = LayoutRect(0, 60, 80, 0);
     EXPECT_TRUE(text->mapToVisualRectInAncestorSpace(container, rect, EdgeInclusive));
+    rect.move(-container->scrolledContentOffset());
     EXPECT_EQ(rect, LayoutRect(0, 10, 80, 0));
 }
 
 TEST_F(VisualRectMappingTest, LayoutInline)
 {
     document().setBaseURLOverride(KURL(ParsedURLString, "http://test.com"));
     setBodyInnerHTML(
         "<style>body { margin: 0; }</style>"
         "<div id='container' style='overflow: scroll; width: 50px; height: 50px'>"
         "  <span><img style='width: 20px; height: 100px'></span>"
         "  <span id=leaf></span></div>");
 
     LayoutBlock* container = toLayoutBlock(getLayoutObjectByElementId("container"));
     LayoutObject* leaf = container->lastChild();
 
     container->setScrollTop(LayoutUnit(50));
     LayoutRect originalRect(0, 60, 20, 80);
     LayoutRect rect = originalRect;
     EXPECT_TRUE(leaf->mapToVisualRectInAncestorSpace(container, rect));
+    rect.move(-container->scrolledContentOffset());
     EXPECT_EQ(rect, LayoutRect(0, 10, 20, 80));
 
     rect = originalRect;
     EXPECT_TRUE(leaf->mapToVisualRectInAncestorSpace(&layoutView(), rect));
     EXPECT_EQ(rect, LayoutRect(0, 10, 20, 40));
     checkPaintInvalidationStateRectMapping(rect, originalRect, *leaf, layoutView(), layoutView());
 
     rect = LayoutRect(0, 60, 80, 0);
     EXPECT_TRUE(leaf->mapToVisualRectInAncestorSpace(container, rect, EdgeInclusive));
+    rect.move(-container->scrolledContentOffset());
     EXPECT_EQ(rect, LayoutRect(0, 10, 80, 0));
 }
 
 TEST_F(VisualRectMappingTest, LayoutView)
 {
     document().setBaseURLOverride(KURL(ParsedURLString, "http://test.com"));
     setBodyInnerHTML(
         "<style>body { margin: 0; }</style>"
         "<div id=frameContainer>"
         "  <iframe id=frame src='http://test.com' width='50' height='50' frameBorder='0'></iframe>"
@@ skipping 143 matching lines @@
     LayoutRect targetOverflowRect = target->localOverflowRectForPaintInvalidation();
     // 140 = width(100) + box_shadow_offset_x(40)
     // 110 = height(90) + box_shadow_offset_y(20)
     EXPECT_EQ(LayoutRect(0, 0, 140, 110), targetOverflowRect);
     LayoutRect rect = targetOverflowRect;
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(target, rect));
     EXPECT_EQ(LayoutRect(0, 0, 140, 110), rect);
 
     rect = targetOverflowRect;
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(container, rect));
+    rect.move(-container->scrolledContentOffset());
     // 2 = target_x(0) + container_border_left(10) - scroll_left(8)
     // 3 = target_y(0) + container_border_top(10) - scroll_top(7)
     // Rect is not clipped by container's overflow clip because of overflow:scroll.
     EXPECT_EQ(LayoutRect(2, 3, 140, 110), rect);
 
     rect = targetOverflowRect;
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(&layoutView(), rect));
     // (2, 3, 140, 100) is first clipped by container's overflow clip, to (10, 10, 50, 80),
     // then is by added container's offset in LayoutView (111, 222).
     EXPECT_EQ(LayoutRect(232, 121, 50, 80), rect);
@@ skipping 43 matching lines @@
 
     LayoutRect rect = targetOverflowRect;
     target->flipForWritingMode(rect);
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(target, rect));
     // This rect is in physical coordinates of target.
     EXPECT_EQ(LayoutRect(0, 0, 140, 110), rect);
 
     rect = targetOverflowRect;
     target->flipForWritingMode(rect);
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(container, rect));
+    rect.move(-container->scrolledContentOffset());
     // -2 = target_physical_x(100) + container_border_left(40) - scroll_left(142)
     // 3 = target_y(0) + container_border_top(10) - scroll_top(7)
     // Rect is clipped by container's overflow clip because of overflow:scroll.
     EXPECT_EQ(LayoutRect(-2, 3, 140, 110), rect);
 
     rect = targetOverflowRect;
     target->flipForWritingMode(rect);
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(&layoutView(), rect));
     // (-2, 3, 140, 100) is first clipped by container's overflow clip, to (40, 10, 50, 80),
     // then is added by container's offset in LayoutView (111, 222).
@@ skipping 117 matching lines @@
     // 110 = height(90) + box_shadow_offset_y(20)
     EXPECT_EQ(LayoutRect(0, 0, 140, 110), targetOverflowRect);
 
     LayoutRect rect = targetOverflowRect;
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(target, rect));
     // This rect is in physical coordinates of target.
     EXPECT_EQ(LayoutRect(0, 0, 140, 110), rect);
 
     rect = targetOverflowRect;
     EXPECT_TRUE(target->mapToVisualRectInAncestorSpace(container, rect));
+    rect.move(-container->scrolledContentOffset());
     // -2 = target_physical_x(100) + container_border_left(40) - scroll_left(142)
     // 3 = target_y(0) + container_border_top(10) - scroll_top(7)
     // Rect is not clipped by container's overflow clip.
     EXPECT_EQ(LayoutRect(-2, 3, 140, 110), rect);
 }
 
 TEST_F(VisualRectMappingTest, DifferentPaintInvalidaitionContainerForAbsolutePosition)
 {
     enableCompositing();
     document().frame()->settings()->setPreferCompositingToLCDTextEnabled(true);
@@ skipping 11 matching lines @@
     scroller->setScrollLeft(LayoutUnit(88));
     document().view()->updateAllLifecyclePhases();
 
     LayoutBlock* normalFlow = toLayoutBlock(getLayoutObjectByElementId("normal-flow"));
     EXPECT_EQ(scroller, &normalFlow->containerForPaintInvalidation());
 
     LayoutRect normalFlowOverflowRect = normalFlow->localOverflowRectForPaintInvalidation();
     EXPECT_EQ(LayoutRect(0, 0, 2000, 2000), normalFlowOverflowRect);
     LayoutRect rect = normalFlowOverflowRect;
     EXPECT_TRUE(normalFlow->mapToVisualRectInAncestorSpace(scroller, rect));
-    EXPECT_EQ(LayoutRect(-88, -77, 2000, 2000), rect);
+    EXPECT_EQ(LayoutRect(0, 0, 2000, 2000), rect);
     checkPaintInvalidationStateRectMapping(rect, normalFlowOverflowRect, *normalFlow, layoutView(), *scroller);
 
     LayoutBlock* stackingContext = toLayoutBlock(getLayoutObjectByElementId("stacking-context"));
     LayoutBlock* absolute = toLayoutBlock(getLayoutObjectByElementId("absolute"));
     EXPECT_EQ(stackingContext, &absolute->containerForPaintInvalidation());
     EXPECT_EQ(stackingContext, absolute->container());
 
     LayoutRect absoluteOverflowRect = absolute->localOverflowRectForPaintInvalidation();
     EXPECT_EQ(LayoutRect(0, 0, 50, 50), absoluteOverflowRect);
     rect = absoluteOverflowRect;
@@ skipping 27 matching lines @@
     LayoutRect absoluteOverflowRect = absolute->localOverflowRectForPaintInvalidation();
     EXPECT_EQ(LayoutRect(0, 0, 50, 50), absoluteOverflowRect);
     LayoutRect rect = absoluteOverflowRect;
     EXPECT_TRUE(absolute->mapToVisualRectInAncestorSpace(stackingContext, rect));
     // -172 = top(50) - y_offset_of_stacking_context(222)
     EXPECT_EQ(LayoutRect(50, -172, 50, 50), rect);
     checkPaintInvalidationStateRectMapping(rect, absoluteOverflowRect, *absolute, layoutView(), *stackingContext);
 }
 
 } // namespace blink