Update the .pak file format to version 2: Make resource ids 16bit

ui/base/resource/data_pack_unittest.cc

 // 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 "base/file_path.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
 #include "base/scoped_temp_dir.h"
 #include "base/string_piece.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 30 matching lines @@
   ScopedTempDir dir;
   ASSERT_TRUE(dir.CreateUniqueTempDir());
   FilePath file = dir.path().Append(FILE_PATH_LITERAL("data.pak"));
 
   std::string one("one");
   std::string two("two");
   std::string three("three");
   std::string four("four");
   std::string fifteen("fifteen");
 
-  std::map<uint32, base::StringPiece> resources;
+  std::map<uint16, base::StringPiece> resources;
   resources.insert(std::make_pair(1, base::StringPiece(one)));
   resources.insert(std::make_pair(2, base::StringPiece(two)));
   resources.insert(std::make_pair(15, base::StringPiece(fifteen)));
   resources.insert(std::make_pair(3, base::StringPiece(three)));
   resources.insert(std::make_pair(4, base::StringPiece(four)));
   ASSERT_TRUE(DataPack::WritePack(file, resources));
 
   // Now try to read the data back in.
   DataPack pack;
   ASSERT_TRUE(pack.Load(file));
 
   base::StringPiece data;
   ASSERT_TRUE(pack.GetStringPiece(1, &data));
   EXPECT_EQ(one, data);
   ASSERT_TRUE(pack.GetStringPiece(2, &data));
   EXPECT_EQ(two, data);
   ASSERT_TRUE(pack.GetStringPiece(3, &data));
   EXPECT_EQ(three, data);
   ASSERT_TRUE(pack.GetStringPiece(4, &data));
   EXPECT_EQ(four, data);
   ASSERT_TRUE(pack.GetStringPiece(15, &data));
   EXPECT_EQ(fifteen, data);
 }
 
 }  // namespace ui