Let mapToVisualRectInAncestorSpace apply ancestor clip if not scrollsOverflow

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

Index: third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
diff --git a/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp b/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
index 4ba7f63c8f90aac44e0554d93c6ec335be1f8e18..984fc3dc30d68897abfc3cbf453fa74bf2941a45 100644
--- a/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
+++ b/third_party/WebKit/Source/core/layout/PaintInvalidationState.cpp
@@ -373,10 +373,7 @@ LayoutRect PaintInvalidationState::computePaintInvalidationRectInBackingForSVG()
         if (m_clipped)
             rect.intersect(m_clipRect);
 #if ASSERT_SAME_RESULT_SLOW_AND_FAST_PATH
-        // TODO(crbug.com/597902): Slow path misses clipping of paintInvalidationContainer.
         LayoutRect slowPathRect = SVGLayoutSupport::clippedOverflowRectForPaintInvalidation(m_currentObject, *m_paintInvalidationContainer);
-        if (m_clipped)
-            slowPathRect.intersect(m_clipRect);
         assertRectsEqual(m_currentObject, m_paintInvalidationContainer, rect, slowPathRect);
 #endif
     } else {
@@ -397,6 +394,10 @@ static void slowMapToVisualRectInAncestorSpace(const LayoutObject& object, const
     } else {
         object.mapToVisualRectInAncestorSpace(&ancestor, rect);
     }
+
+    // LayoutObject::mapToVisualRectInAncestorSpace() doesn't apply overflow clip of ancestor.

[chrishtr, 2016/04/06 23:18:19]

Do any other call sites of mapToVisualRectInAncestorSpace need to apply this
clipping? If so please file a bug.

[Xianzhu, 2016/04/06 23:37:33]

Didn't think of this. Just looked at several callsites and I think we should
apply clipping there in the same way as paint invalidation rects. Will reopen
crbug.com/597902.

+    if (ancestor.isBox() && !ancestor.isLayoutView() && !toLayoutBox(ancestor).scrollsOverflow())
+        rect.intersect(toLayoutBox(ancestor).overflowClipRect(LayoutPoint()));
 }
 
 void PaintInvalidationState::mapLocalRectToPaintInvalidationBacking(LayoutRect& rect) const
@@ -412,9 +413,6 @@ void PaintInvalidationState::mapLocalRectToPaintInvalidationBacking(LayoutRect&
         if (m_clipped)
             rect.intersect(m_clipRect);
 #if ASSERT_SAME_RESULT_SLOW_AND_FAST_PATH
-        // TODO(crbug.com/597902): Slow path misses clipping of paintInvalidationContainer.
-        if (m_clipped)
-            slowPathRect.intersect(m_clipRect);
         assertRectsEqual(m_currentObject, *m_paintInvalidationContainer, rect, slowPathRect);
 #endif
     } else {