Deleted OS_WIN and all Windows specific files from base.

base/environment.h

Index: base/environment.h
diff --git a/base/environment.h b/base/environment.h
index c8811e27eee354ccb6e4b80939327d3ffb622877..2767730ec5b2d262c254dbe8b6d0f418ebe0f03b 100644
--- a/base/environment.h
+++ b/base/environment.h
@@ -47,26 +47,7 @@ class BASE_EXPORT Environment {
 };
 
 
-#if defined(OS_WIN)
-
-typedef string16 NativeEnvironmentString;
-typedef std::map<NativeEnvironmentString, NativeEnvironmentString>
-    EnvironmentMap;
-
-// Returns a modified environment vector constructed from the given environment
-// and the list of changes given in |changes|. Each key in the environment is
-// matched against the first element of the pairs. In the event of a match, the
-// value is replaced by the second of the pair, unless the second is empty, in
-// which case the key-value is removed.
-//
-// This Windows version takes and returns a Windows-style environment block
-// which is a concatenated list of null-terminated 16-bit strings. The end is
-// marked by a double-null terminator. The size of the returned string will
-// include the terminators.
-BASE_EXPORT string16 AlterEnvironment(const wchar_t* env,
-                                      const EnvironmentMap& changes);
-
-#elif defined(OS_POSIX)
+#if defined(OS_POSIX)
 
 typedef std::string NativeEnvironmentString;
 typedef std::map<NativeEnvironmentString, NativeEnvironmentString>