Add code to be able to detect windows7 in GetWinVersion.

base/win_util.cc

Index: base/win_util.cc
===================================================================
--- base/win_util.cc	(revision 9582)
+++ base/win_util.cc	(working copy)
@@ -39,9 +39,9 @@
   static bool checked_version = false;
   static WinVersion win_version = WINVERSION_PRE_2000;
   if (!checked_version) {
-    OSVERSIONINFO version_info;
+    OSVERSIONINFOEX version_info;
     version_info.dwOSVersionInfoSize = sizeof version_info;
-    GetVersionEx(&version_info);
+    GetVersionEx(reinterpret_cast<OSVERSIONINFO*>(&version_info));
     if (version_info.dwMajorVersion == 5) {
       switch (version_info.dwMinorVersion) {
         case 0:
@@ -55,8 +55,19 @@
           win_version = WINVERSION_SERVER_2003;
           break;
       }
-    } else if (version_info.dwMajorVersion >= 6) {
-      win_version = WINVERSION_VISTA;
+    } else if (version_info.dwMajorVersion == 6) {
+      if (version_info.wProductType != VER_NT_WORKSTATION) {
+        // 2008 is 6.0, and 2008 R2 is 6.1.
+        win_version = WINVERSION_2008;
+      } else {
+        if (version_info.dwMinorVersion == 0) {
+          win_version = WINVERSION_VISTA;
+        } else {
+          win_version = WINVERSION_WIN7;
+        }
+      }
+    } else if (version_info.dwMajorVersion > 6) {
+      win_version = WINVERSION_WIN7;
     }
     checked_version = true;
   }