Add more missing closing namespace comments.

third_party/WebKit/Source/platform/geometry/DoubleSize.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 "platform/geometry/DoubleSize.h"
 #include "platform/geometry/LayoutSize.h"
 
 #include <limits>
 #include <math.h>
 
 namespace blink {
 
 DoubleSize::DoubleSize(const LayoutSize& size)
     : m_width(size.width().toDouble())
     , m_height(size.height().toDouble())
 {
 }
 
 bool DoubleSize::isZero() const
 {
     return fabs(m_width) < std::numeric_limits<double>::epsilon() && fabs(m_height) < std::numeric_limits<double>::epsilon();
 }
 
-}
+} // namespace blink