ui/gfx: Add ToString() function to Size class.

ui/gfx/size.cc

-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2011 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 "ui/gfx/size.h"
 
 #if defined(OS_WIN)
 #include <windows.h>
 #elif defined(OS_MACOSX)
 #include <CoreGraphics/CGGeometry.h>
 #endif
 
-#include <ostream>
-
 #include "base/logging.h"
+#include "base/stringprintf.h"
 
 namespace gfx {
 
+Size::Size() : width_(0), height_(0) {}
+
 Size::Size(int width, int height) {
   set_width(width);
   set_height(height);
 }
 
 #if defined(OS_MACOSX)
 Size::Size(const CGSize& s) {
   set_width(s.width);
   set_height(s.height);
 }
@@ skipping 27 matching lines @@
 }
 
 void Size::set_height(int height) {
   if (height < 0) {
     NOTREACHED() << "negative height:" << height;
     height = 0;
   }
   height_ = height;
 }
 
-std::ostream& operator<<(std::ostream& out, const gfx::Size& s) {
-  return out << s.width() << "x" << s.height();
+std::string Size::ToString() const {
+  return base::StringPrintf("%dx%d", width_, height_);
 }
 
 }  // namespace gfx