Add scale factor tag to data packs

ui/base/resource/data_pack.h

 // Copyright (c) 2012 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.
 
 // DataPack represents a read-only view onto an on-disk file that contains
 // (key, value) pairs of data.  It's used to store static resources like
 // translation strings and images.
 
 #ifndef UI_BASE_RESOURCE_DATA_PACK_H_
 #define UI_BASE_RESOURCE_DATA_PACK_H_
@@ skipping 34 matching lines @@
   static bool WritePack(const FilePath& path,
                         const std::map<uint16, base::StringPiece>& resources,
                         TextEncodingType textEncodingType);
 
   // ResourceHandle implementation:
   virtual bool GetStringPiece(uint16 resource_id,
                               base::StringPiece* data) const OVERRIDE;
   virtual base::RefCountedStaticMemory* GetStaticMemory(
       uint16 resource_id) const OVERRIDE;
   virtual TextEncodingType GetTextEncodingType() const OVERRIDE;
+  virtual float GetScaleFactor() const OVERRIDE;
+
+  void set_scale_factor(float scale_factor) { scale_factor_ = scale_factor; }

[sky, 2012/04/25 21:11:42]

Do you really need a setter here? A setter implies you can change after the
fact, which I don't think we want, right? How about passing to constructor and
making const.

nit: non-virtual before virtual.

[sail, 2012/04/25 22:18:35]

Done.
Removed setter.

 
  private:
   // The memory-mapped data.
   scoped_ptr<file_util::MemoryMappedFile> mmap_;
 
   // Number of resources in the data.
   size_t resource_count_;
 
   // Type of encoding for text resources.
   TextEncodingType text_encoding_type_;
 
+  // The scale factor of image resources.

[sky, 2012/04/25 21:11:42]

This isn't really clear. It reads like all images are scaled by this, which I
don't think is what it does. 

[sail, 2012/04/25 22:18:35]

Done.

+  float scale_factor_;
+
   DISALLOW_COPY_AND_ASSIGN(DataPack);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_RESOURCE_DATA_PACK_H_