[NaCl SDK] Add nacl_io and sdk_util namespaces.

native_client_sdk/src/libraries/sdk_util/atomicops.h

Index: native_client_sdk/src/libraries/sdk_util/atomicops.h
diff --git a/native_client_sdk/src/libraries/sdk_util/atomicops.h b/native_client_sdk/src/libraries/sdk_util/atomicops.h
index cd07b4411868fb9c15694db614be7777f16c9151..b0e9431b4f4a851d5283a0dd35b5422996c6f136 100644
--- a/native_client_sdk/src/libraries/sdk_util/atomicops.h
+++ b/native_client_sdk/src/libraries/sdk_util/atomicops.h
@@ -9,6 +9,9 @@
 #ifndef WIN32
 
 #include <stdint.h>
+
+namespace sdk_util {
+
 typedef int32_t Atomic32;
 
 #ifndef __llvm__
@@ -39,7 +42,9 @@ inline Atomic32 AtomicXorFetch(volatile Atomic32* ptr, Atomic32 value) {
   return __sync_xor_and_fetch(ptr, value);
 }
 
-#else
+}  // namespace sdk_util
+
+#else  // ifndef WIN32
 
 #include <windows.h>
 
@@ -49,6 +54,8 @@ inline Atomic32 AtomicXorFetch(volatile Atomic32* ptr, Atomic32 value) {
 #undef PostMessage
 #undef interface
 
+namespace sdk_util {
+
 typedef long Atomic32;
 
 /* Windows.h already defines a MemoryBarrier macro. */
@@ -96,7 +103,8 @@ inline Atomic32 AtomicXorFetch(volatile Atomic32* ptr, Atomic32 value) {
   return newval;
 }
 
-#endif
+}  // namespace sdk_util
 
+#endif  // ifndef WIN32
 
 #endif  /* LIBRARIES_SDK_UTIL_ATOMICOPS_H_ */