Enable "extern template" under MSVC

base/logging.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 "base/logging.h"
 
 #if defined(OS_WIN)
 #include <io.h>
 #include <windows.h>
 typedef HANDLE FileHandle;
@@ skipping 426 matching lines @@
 }
 
 void SetLogMessageHandler(LogMessageHandlerFunction handler) {
   log_message_handler = handler;
 }
 
 LogMessageHandlerFunction GetLogMessageHandler() {
   return log_message_handler;
 }
 
-// MSVC doesn't like complex extern templates and DLLs.
-#if !defined(COMPILER_MSVC)
 // Explicit instantiations for commonly used comparisons.
 template std::string* MakeCheckOpString<int, int>(
     const int&, const int&, const char* names);
 template std::string* MakeCheckOpString<unsigned long, unsigned long>(
     const unsigned long&, const unsigned long&, const char* names);
 template std::string* MakeCheckOpString<unsigned long, unsigned int>(
     const unsigned long&, const unsigned int&, const char* names);
 template std::string* MakeCheckOpString<unsigned int, unsigned long>(
     const unsigned int&, const unsigned long&, const char* names);
 template std::string* MakeCheckOpString<std::string, std::string>(
     const std::string&, const std::string&, const char* name);
-#endif
 
 #if !defined(NDEBUG)
 // Displays a message box to the user with the error message in it.
 // Used for fatal messages, where we close the app simultaneously.
 // This is for developers only; we don't use this in circumstances
 // (like release builds) where users could see it, since users don't
 // understand these messages anyway.
 void DisplayDebugMessageInDialog(const std::string& str) {
   if (str.empty())
     return;
@@ skipping 335 matching lines @@
     return *log_file_name;
   return std::wstring();
 }
 #endif
 
 }  // namespace logging
 
 std::ostream& std::operator<<(std::ostream& out, const wchar_t* wstr) {
   return out << base::WideToUTF8(std::wstring(wstr));
 }