Make the windows_version.h functions threadsafe by using a singleton.

chrome/browser/diagnostics/recon_diagnostics.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 "chrome/browser/diagnostics/recon_diagnostics.h"
 
 #include <string>
 
 #include "base/file_util.h"
 #include "base/json/json_reader.h"
@@ skipping 30 matching lines @@
 
 // Check that the flavor of the operating system is supported.
 class OperatingSystemTest : public DiagnosticTest {
  public:
   OperatingSystemTest() : DiagnosticTest(ASCIIToUTF16("Operating System")) {}
 
   virtual int GetId() { return 0; }
 
   virtual bool ExecuteImpl(DiagnosticsModel::Observer* observer) {
     int version = 0;
-    int major = 0;
-    int minor = 0;
+    const int* service_pack;
 #if defined(OS_WIN)
     version = base::win::GetVersion();
     if (version < base::win::VERSION_XP) {
       RecordFailure(ASCIIToUTF16("Windows 2000 or earlier"));
       return false;
     }
-    base::win::GetServicePackLevel(&major, &minor);
-    if ((version == base::win::VERSION_XP) && (major < 2)) {
+    service_pack = base::win::OSInfo::GetInstance()->service_pack();
+    if ((version == base::win::VERSION_XP) && (service_pack[0] < 2)) {
       RecordFailure(ASCIIToUTF16("XP Service Pack 1 or earlier"));
       return false;
     }
 #else
     // TODO(port): define the OS criteria for Linux and Mac.
 #endif  // defined(OS_WIN)
     RecordSuccess(ASCIIToUTF16(StringPrintf("%s %s (%d [%d:%d])",
         base::SysInfo::OperatingSystemName().c_str(),
         base::SysInfo::OperatingSystemVersion().c_str(),
-        version, major, minor)));
+        version, service_pack[0], service_pack[1])));
     return true;
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(OperatingSystemTest);
 };
 
 // Check if any conflicting DLLs are loaded.
 class ConflictingDllsTest : public DiagnosticTest {
  public:
@@ skipping 340 matching lines @@
   path = path.Append(chrome::kBookmarksFileName);
   return new JSONTest(path, ASCIIToUTF16("BookMarks JSON"), 2 * kOneMeg);
 }
 
 DiagnosticTest* MakeLocalStateTest() {
   FilePath path;
   PathService::Get(chrome::DIR_USER_DATA, &path);
   path = path.Append(chrome::kLocalStateFilename);
   return new JSONTest(path, ASCIIToUTF16("Local State JSON"), 50 * kOneKilo);
 }