[NaCl SDK] Add nacl_io and sdk_util namespaces.

native_client_sdk/src/libraries/nacl_io/mount_http.h

Index: native_client_sdk/src/libraries/nacl_io/mount_http.h
diff --git a/native_client_sdk/src/libraries/nacl_io/mount_http.h b/native_client_sdk/src/libraries/nacl_io/mount_http.h
index e804f37d5a92193860a83832d39f928a3849360e..29a50271c12a63016927b76a6efc1b3814adafb9 100644
--- a/native_client_sdk/src/libraries/nacl_io/mount_http.h
+++ b/native_client_sdk/src/libraries/nacl_io/mount_http.h
@@ -11,9 +11,12 @@
 #include "nacl_io/pepper_interface.h"
 #include "nacl_io/typed_mount_factory.h"
 
-class MountNode;
 class MountHttpMock;
 
+namespace nacl_io {
+
+class MountNode;
+
 std::string NormalizeHeaderKey(const std::string& s);
 
 class MountHttp : public Mount {
@@ -55,7 +58,9 @@ class MountHttp : public Mount {
 
   friend class TypedMountFactory<MountHttp>;
   friend class MountNodeHttp;
-  friend class MountHttpMock;
+  friend class ::MountHttpMock;
 };
 
+}  // namespace nacl_io
+
 #endif  // LIBRARIES_NACL_IO_MOUNT_HTTP_H_