Ignore overflow clip on root layer if HitTestRequest::IgnoreClipping is set.

Source/core/paint/DeprecatedPaintLayerClipper.cpp

Index: Source/core/paint/DeprecatedPaintLayerClipper.cpp
diff --git a/Source/core/paint/DeprecatedPaintLayerClipper.cpp b/Source/core/paint/DeprecatedPaintLayerClipper.cpp
index fa3a00b857a1562cf5f94499d269c157f1a1b779..2fd415cb4019d3956f72c40bedc8d0f8a2603ec2 100644
--- a/Source/core/paint/DeprecatedPaintLayerClipper.cpp
+++ b/Source/core/paint/DeprecatedPaintLayerClipper.cpp
@@ -234,7 +234,7 @@ void DeprecatedPaintLayerClipper::calculateRects(const ClipRectsContext& context
     // Update the clip rects that will be passed to child layers.
     if (m_layoutObject.hasOverflowClip()) {
         // This layer establishes a clip of some kind.
-        if (!isClippingRoot || context.respectOverflowClip == RespectOverflowClip) {
+        if (shouldRespectOverflowClip(context)) {
             foregroundRect.intersect(toLayoutBox(m_layoutObject).overflowClipRect(offset, context.scrollbarRelevancy));
             if (m_layoutObject.style()->hasBorderRadius())
                 foregroundRect.setHasRadius(true);
@@ -251,12 +251,12 @@ void DeprecatedPaintLayerClipper::calculateRects(const ClipRectsContext& context
             LayoutRect layerBoundsWithVisualOverflow = toLayoutBox(m_layoutObject).visualOverflowRect();
             toLayoutBox(m_layoutObject).flipForWritingMode(layerBoundsWithVisualOverflow); // DeprecatedPaintLayer are in physical coordinates, so the overflow has to be flipped.
             layerBoundsWithVisualOverflow.moveBy(offset);
-            if (!isClippingRoot || context.respectOverflowClip == RespectOverflowClip)
+            if (shouldRespectOverflowClip(context))
                 backgroundRect.intersect(layerBoundsWithVisualOverflow);
         } else {
             LayoutRect bounds = toLayoutBox(m_layoutObject).borderBoxRect();
             bounds.moveBy(offset);
-            if (!isClippingRoot || context.respectOverflowClip == RespectOverflowClip)
+            if (shouldRespectOverflowClip(context))
                 backgroundRect.intersect(bounds);
         }
     }
@@ -300,7 +300,7 @@ void DeprecatedPaintLayerClipper::calculateClipRects(const ClipRectsContext& con
 
     adjustClipRectsForChildren(m_layoutObject, clipRects);
 
-    if ((m_layoutObject.hasOverflowClip() && (context.respectOverflowClip == RespectOverflowClip || !isClippingRoot)) || m_layoutObject.hasClip()) {
+    if ((m_layoutObject.hasOverflowClip() && shouldRespectOverflowClip(context)) || m_layoutObject.hasClip()) {
         // This offset cannot use convertToLayerCoords, because sometimes our rootLayer may be across
         // some transformed layer boundary, for example, in the DeprecatedPaintLayerCompositor overlapMap, where
         // clipRects are needed in view space.
@@ -371,4 +371,19 @@ DeprecatedPaintLayer* DeprecatedPaintLayerClipper::clippingRootForPainting() con
     return 0;
 }
 
+bool DeprecatedPaintLayerClipper::shouldRespectOverflowClip(const ClipRectsContext& context) const
+{
+    DeprecatedPaintLayer* layer = m_layoutObject.layer();
+    if (layer != context.rootLayer)
+        return true;
+
+    if (context.respectOverflowClip == IgnoreOverflowClip)
+        return false;
+
+    if (layer->isRootLayer() && context.respectOverflowClipForViewport == IgnoreOverflowClip)
+        return false;
+
+    return true;
+}
+
 } // namespace blink