Always apply parent clips to selection rects when painting.

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

 // Copyright 2014 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/paint/BoxClipper.h"
 
 #include "core/layout/LayoutBox.h"
 #include "core/paint/ObjectPaintProperties.h"
 #include "core/paint/PaintInfo.h"
 #include "core/paint/PaintLayer.h"
@@ skipping 30 matching lines @@
 
     if (!isControlClip && !isOverflowOrContainmentClip)
         return;
 
     LayoutRect clipRect = isControlClip ? m_box.controlClipRect(accumulatedOffset) : m_box.overflowClipRect(accumulatedOffset);
     FloatRoundedRect clipRoundedRect(0, 0, 0, 0);
     bool hasBorderRadius = m_box.style()->hasBorderRadius();
     if (hasBorderRadius)
         clipRoundedRect = m_box.style()->getRoundedInnerBorderFor(LayoutRect(accumulatedOffset, m_box.size()));
 
-    if (contentsClipBehavior == SkipContentsClipIfPossible) {
+    // Selection does not affect visual overflow, so this optimization is invalid if selection
+    // is present.
+    if (contentsClipBehavior == SkipContentsClipIfPossible && box.getSelectionState() == SelectionNone) {
         LayoutRect contentsVisualOverflow = m_box.contentsVisualOverflowRect();
         if (contentsVisualOverflow.isEmpty())
             return;
 
         LayoutRect conservativeClipRect = clipRect;
         if (hasBorderRadius)
             conservativeClipRect.intersect(LayoutRect(clipRoundedRect.radiusCenterRect()));
         conservativeClipRect.moveBy(-accumulatedOffset);
         if (m_box.hasLayer())
             conservativeClipRect.move(m_box.scrolledContentOffset());
@@ skipping 13 matching lines @@
 BoxClipper::~BoxClipper()
 {
     if (m_clipType == DisplayItem::UninitializedType)
         return;
 
     ASSERT(m_box.hasControlClip() || (m_box.hasOverflowClip() && !m_box.layer()->isSelfPaintingLayer()) || m_box.style()->containsPaint());
     m_paintInfo.context.getPaintController().endItem<EndClipDisplayItem>(m_box, DisplayItem::clipTypeToEndClipType(m_clipType));
 }
 
 } // namespace blink