LayoutObject::absoluteBoundingBoxRectForRange() should take EphemeralRange

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

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2011 Apple Inc.
  *               All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
  *               (http://www.torchmobile.com/)
@@ skipping 987 matching lines @@
 
 IntRect LayoutObject::absoluteElementBoundingBoxRect() const {
   Vector<LayoutRect> rects;
   const LayoutBoxModelObject& container = enclosingLayer()->layoutObject();
   addElementVisualOverflowRects(
       rects, LayoutPoint(localToAncestorPoint(FloatPoint(), &container)));
   return container.localToAbsoluteQuad(FloatQuad(FloatRect(unionRect(rects))))
       .enclosingBoundingBox();
 }
 
-FloatRect LayoutObject::absoluteBoundingBoxRectForRange(const Range* range) {
-  if (!range || !range->startContainer())
+FloatRect LayoutObject::absoluteBoundingBoxRectForRange(
+    const EphemeralRange& range) {
+  if (range.isNull() || !range.startPosition().computeContainerNode())
     return FloatRect();
 
-  range->ownerDocument().updateStyleAndLayout();
+  range.document().updateStyleAndLayout();
 
-  Vector<FloatQuad> quads;
-  range->textQuads(quads);
-
+  Vector<FloatQuad> quads = textQuad(range);

[Xiaocheng, 2017/03/30 18:46:19]

Sorry, my mistake.

I did an experiment and found that this doesn't invoke move assignment, but copy
assignment instead.

Please switch back to passing a |Vector<FloatQuad>*| to the function for output
value.

Note: Google C++ style guide prohibits using non-constant reference argument for
output value:

https://google.github.io/styleguide/cppguide.html#Reference_Arguments

   FloatRect result;
   for (size_t i = 0; i < quads.size(); ++i)
     result.unite(quads[i].boundingBox());
 
   return result;
 }
 
 void LayoutObject::addAbsoluteRectForLayer(IntRect& result) {
   if (hasLayer())
     result.unite(absoluteBoundingBoxRect());
@@ skipping 2599 matching lines @@
     const blink::LayoutObject* root = object1;
     while (root->parent())
       root = root->parent();
     root->showLayoutTreeAndMark(object1, "*", object2, "-", 0);
   } else {
     WTFLogAlways("%s", "Cannot showLayoutTree. Root is (nil)");
   }
 }
 
 #endif