gpu: Disallow null client ids in Gen* functions

gpu/command_buffer/service/gles2_cmd_decoder.cc

 // Copyright (c) 2012 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.
 
 #include "gpu/command_buffer/service/gles2_cmd_decoder.h"
 
 #include <limits.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <stdio.h>
@@ skipping 175 matching lines @@
     manager->GetClientId(object->service_id(), &client_id);
   }
   return client_id;
 }
 
 template <typename OBJECT_TYPE>
 GLuint GetServiceId(const OBJECT_TYPE* object) {
   return object ? object->service_id() : 0;
 }
 
-bool CheckUniqueIds(GLsizei n, const GLuint* client_ids) {
+bool CheckUniqueAndNonNullIds(GLsizei n, const GLuint* client_ids) {
   if (n <= 0)
     return true;
   std::unordered_set<uint32_t> unique_ids(client_ids, client_ids + n);
-  return unique_ids.size() == static_cast<size_t>(n);
+  return (unique_ids.size() == static_cast<size_t>(n)) &&
+         (unique_ids.find(0) == unique_ids.end());
 }
 
 struct Vec4f {
   explicit Vec4f(const Vec4& data) {
     data.GetValues(v);
   }
 
   GLfloat v[4];
 };
 
@@ skipping 16579 matching lines @@
 }
 
 // Include the auto-generated part of this file. We split this because it means
 // we can easily edit the non-auto generated parts right here in this file
 // instead of having to edit some template or the code generator.
 #include "base/macros.h"
 #include "gpu/command_buffer/service/gles2_cmd_decoder_autogen.h"
 
 }  // namespace gles2
 }  // namespace gpu