Grab bag of clang fixes for Windows code

ui/shell_dialogs/select_file_dialog_win_unittest.cc

 // 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.
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/shell_dialogs/select_file_dialog.h"
 #include "ui/shell_dialogs/select_file_dialog_win.h"
 
 TEST(ShellDialogsWin, AppendExtensionIfNeeded) {
   struct AppendExtensionTestCase {
-    wchar_t* filename;
-    wchar_t* filter_selected;
-    wchar_t* suggested_ext;
-    wchar_t* expected_filename;
+    const wchar_t* filename;
+    const wchar_t* filter_selected;
+    const wchar_t* suggested_ext;
+    const wchar_t* expected_filename;
   } test_cases[] = {
     // Known extensions, with or without associated MIME types, should not get
     // an extension appended.
     { L"sample.html",    L"*.txt",     L"txt",     L"sample.html" },
     { L"sample.reg",     L"*.txt",     L"txt",     L"sample.reg" },
 
     // An unknown extension, or no extension, should get the default extension
     // appended.
     { L"sample.unknown", L"*.txt",     L"txt",     L"sample.unknown.txt" },
     { L"sample",         L"*.txt",     L"txt",     L"sample.txt" },
@@ skipping 12 matching lines @@
   };
 
   for (size_t i = 0; i < arraysize(test_cases); ++i) {
     EXPECT_EQ(std::wstring(test_cases[i].expected_filename),
               ui::AppendExtensionIfNeeded(test_cases[i].filename,
                                           test_cases[i].filter_selected,
                                           test_cases[i].suggested_ext));
   }
 }