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

chrome/browser/diagnostics/recon_diagnostics.cc

Index: chrome/browser/diagnostics/recon_diagnostics.cc
===================================================================
--- chrome/browser/diagnostics/recon_diagnostics.cc	(revision 80528)
+++ chrome/browser/diagnostics/recon_diagnostics.cc	(working copy)
@@ -48,16 +48,15 @@
 
   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;
     }
@@ -67,7 +66,7 @@
     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;
   }