Add support for loading pak files from arbitrary file regions.

ui/base/resource/resource_bundle.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.
 
 #ifndef UI_BASE_RESOURCE_RESOURCE_BUNDLE_H_
 #define UI_BASE_RESOURCE_RESOURCE_BUNDLE_H_
 
 #include <map>
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/containers/hash_tables.h"
+#include "base/files/file.h"
 #include "base/files/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/strings/string16.h"
 #include "base/strings/string_piece.h"
 #include "build/build_config.h"
 #include "ui/base/layout.h"
 #include "ui/base/ui_base_export.h"
 #include "ui/gfx/font_list.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/native_widget_types.h"
 
 class SkBitmap;
 
 namespace base {
-class File;
 class Lock;
 class RefCountedStaticMemory;
 }
 
 namespace ui {
 
 class DataPack;
 class ResourceHandle;
 
 // ResourceBundle is a central facility to load images and other resources,
@@ skipping 119 matching lines @@
   // or just the pack file name otherwise (the delegate may optionally override
   // this value). |scale_factor| is the scale of images in this resource pak
   // relative to the images in the 1x resource pak. This method is not thread
   // safe! You should call it immediately after calling InitSharedInstance.
   void AddDataPackFromPath(const base::FilePath& path,
                            ScaleFactor scale_factor);
 
   // Same as above but using an already open file.
   void AddDataPackFromFile(base::File file, ScaleFactor scale_factor);
 
+  // Same as above but using only a region (offset + size) of the file.
+  void AddDataPackFromFileRegion(base::File file,
+                                 const base::File::Region& region,
+                                 ScaleFactor scale_factor);
+
   // Same as AddDataPackFromPath but does not log an error if the pack fails to
   // load.
   void AddOptionalDataPackFromPath(const base::FilePath& path,
                                    ScaleFactor scale_factor);
 
   // Changes the locale for an already-initialized ResourceBundle, returning the
   // name of the newly-loaded locale.  Future calls to get strings will return
   // the strings for this new locale.  This has no effect on existing or future
   // image resources.  |locale_resources_data_| is protected by a lock for the
   // duration of the swap, as GetLocalizedString() may be concurrently invoked
@@ skipping 232 matching lines @@
 
   DISALLOW_COPY_AND_ASSIGN(ResourceBundle);
 };
 
 }  // namespace ui
 
 // TODO(beng): Someday, maybe, get rid of this.
 using ui::ResourceBundle;
 
 #endif  // UI_BASE_RESOURCE_RESOURCE_BUNDLE_H_