More clear comment for ValidateStructHeader.

mojo/public/cpp/bindings/lib/bindings_serialization.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_PUBLIC_CPP_BINDINGS_LIB_BINDINGS_SERIALIZATION_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_LIB_BINDINGS_SERIALIZATION_H_
 
 #include <vector>
 
 #include "mojo/public/cpp/system/core.h"
@@ skipping 53 matching lines @@
 // Note: This function doesn't validate the encoded pointer and handle values.
 template <typename T>
 inline void Decode(T* obj, std::vector<Handle>* handles) {
   DecodePointer(&obj->offset, &obj->ptr);
   if (obj->ptr)
     obj->ptr->DecodePointersAndHandles(handles);
 }
 
 // If returns true, this function also claims the memory range of the size
 // specified in the struct header, starting from |data|.
+// Note: |min_num_bytes| must be no less than sizeof(StructHeader).
 bool ValidateStructHeader(const void* data,
                           uint32_t min_num_bytes,
                           uint32_t min_num_fields,
                           BoundsChecker* bounds_checker);
 
 }  // namespace internal
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_BINDINGS_SERIALIZATION_H_