Make NTPTile copyable.

components/ntp_tiles/ntp_tile.h

 // Copyright 2016 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_NTP_TILES_NTP_TILE_H_
 #define COMPONENTS_NTP_TILES_NTP_TILE_H_
 
 #include <vector>
 
 #include "base/files/file_path.h"
@@ skipping 25 matching lines @@
 
   // Only valid for source == WHITELIST (empty otherwise).
   base::FilePath whitelist_icon_path;
 
   NTPTile();
   ~NTPTile();
 
   NTPTile(NTPTile&&);
   NTPTile& operator=(NTPTile&&);
 
+  NTPTile Copy() const;

[Marc Treib, 2016/09/15 09:10:27]

Hm, at this point, we might as well just remove the DISALLOW_COPY_AND_ASSIGN and
let the thing be copyable the regular way. (Then we probably could also remove
the move ctor and move assignment implementations.)
WDYT?

[sfiera, 2016/09/21 08:56:28]

Sure, done. (I think I was channeling google3's extreme implicit-copy avoidance)

[Marc Treib, 2016/09/21 08:58:06]

We mostly have that in Chromium as well, but in this case it's IMO fine to have
it copyable. You might want to put a "Copy and assign allowed" comment in place
of the DISALLOW_COPY_AND_ASSIGN.

[sfiera, 2016/09/21 09:12:58]

I had to add the default copy constructor explicitly for a compiler check, so I
figure I'll let that stand as the indication that copy is allowed.

+
  private:
   DISALLOW_COPY_AND_ASSIGN(NTPTile);
 };
 
 using NTPTilesVector = std::vector<NTPTile>;
 
 }  // namespace ntp_tiles
 
 #endif  // COMPONENTS_NTP_TILES_NTP_TILE_H_