components: Add out-of-line copy ctors for complex classes.

components/favicon/core/favicon_url.h

 // 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.
 
 #ifndef COMPONENTS_FAVICON_CORE_FAVICON_URL_
 #define COMPONENTS_FAVICON_CORE_FAVICON_URL_
 
 #include <vector>
 
 #include "components/favicon_base/favicon_types.h"
 #include "ui/gfx/geometry/size.h"
 #include "url/gurl.h"
 
 namespace favicon {
 
 // Stores metadata about a given favicon.
 struct FaviconURL {
   FaviconURL();
   FaviconURL(const GURL& url,
              favicon_base::IconType type,
              const std::vector<gfx::Size>& sizes);
+  FaviconURL(const FaviconURL& other);
   ~FaviconURL();
 
   // The url of the icon.
   GURL icon_url;
 
   // The type of the icon.
   favicon_base::IconType icon_type;
 
   // Icon's bitmaps' size.
   std::vector<gfx::Size> icon_sizes;
 };
 
 }  // namespace favicon
 
 #endif  // COMPONENTS_FAVICON_CORE_FAVICON_URL_