Deleted OS_WIN and all Windows specific files from base.

base/strings/safe_sprintf.cc

Index: base/strings/safe_sprintf.cc
diff --git a/base/strings/safe_sprintf.cc b/base/strings/safe_sprintf.cc
index b1fcf45b24f7a19f76eb6a175abc82467daa41ea..26ad4c74cb35357d3f1c9285fd1490dc86137d6a 100644
--- a/base/strings/safe_sprintf.cc
+++ b/base/strings/safe_sprintf.cc
@@ -115,7 +115,7 @@ class Buffer {
 // doesn't really implement constexpr yet so it doesn't complain, but clang
 // does.
 #if __cplusplus >= 201103 && !defined(OS_ANDROID) && !defined(OS_MACOSX) && \
-    !defined(OS_IOS) && !(defined(__clang__) && defined(OS_WIN))
+    !defined(OS_IOS) && !(defined(__clang__))
     COMPILE_ASSERT(kSSizeMaxConst == \
                    static_cast<size_t>(std::numeric_limits<ssize_t>::max()),
                    kSSizeMax_is_the_max_value_of_an_ssize_t);