clang/win: Let remaining chromium_code targets build with -Wextra.

chrome/browser/media_galleries/fileapi/iapps_finder_impl_win_browsertest.cc

 // Copyright 2013 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/base64.h"
 #include "base/base_paths_win.h"
 #include "base/bind.h"
 #include "base/files/file_util.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/logging.h"
@@ skipping 43 matching lines @@
   }
 
   const base::FilePath& music_dir() {
     return music_dir_.path();
   }
 
   void WritePrefFile(const std::string& data) {
     base::FilePath pref_dir =
         app_data_dir().AppendASCII("Apple Computer").AppendASCII("iTunes");
     ASSERT_TRUE(base::CreateDirectory(pref_dir));
-    ASSERT_EQ(data.size(),
+    ASSERT_EQ(static_cast<int>(data.size()),
               base::WriteFile(pref_dir.AppendASCII("iTunesPrefs.xml"),
                               data.data(), data.size()));
   }
 
   void TouchDefault() {
     base::FilePath default_dir = music_dir().AppendASCII("iTunes");
     ASSERT_TRUE(base::CreateDirectory(default_dir));
     TouchFile(default_dir.AppendASCII("iTunes Music Library.xml"));
   }
 
@@ skipping 110 matching lines @@
       "</plist>", EncodePath(library_xml).c_str());
   WritePrefFile(xml);
   TestFindITunesLibrary();
   EXPECT_TRUE(test_finder_callback_called());
   EXPECT_TRUE(EmptyResult());
 }
 
 }  // namespace
 
 }  // namespace iapps