Mojo C++ bindings: fix inlined union validation.

mojo/public/cpp/bindings/lib/validation_util.cc

 // Copyright 2015 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 "mojo/public/cpp/bindings/lib/validation_util.h"
 
 #include <stdint.h>
 
 #include <limits>
 
@@ skipping 28 matching lines @@
 
   if (!validation_context->ClaimMemory(data, header->num_bytes)) {
     ReportValidationError(validation_context,
                           VALIDATION_ERROR_ILLEGAL_MEMORY_RANGE);
     return false;
   }
 
   return true;
 }
 
-bool ValidateUnionHeaderAndClaimMemory(const void* data,
-                                       bool inlined,
-                                       ValidationContext* validation_context) {
+bool ValidateNonInlinedUnionHeaderAndClaimMemory(
+    const void* data,
+    ValidationContext* validation_context) {
   if (!IsAligned(data)) {
     ReportValidationError(validation_context,
                           VALIDATION_ERROR_MISALIGNED_OBJECT);
     return false;
   }
 
-  // If the union is inlined in another structure its memory was already
-  // claimed.
-  // This ONLY applies to the union itself, NOT anything which the union points
-  // to.
-  if (!inlined && !validation_context->ClaimMemory(data, kUnionDataSize)) {
+  if (!validation_context->ClaimMemory(data, kUnionDataSize) ||
+      *static_cast<const uint32_t*>(data) != kUnionDataSize) {
     ReportValidationError(validation_context,
                           VALIDATION_ERROR_ILLEGAL_MEMORY_RANGE);
     return false;
   }
 
   return true;
 }
 
 bool ValidateMessageIsRequestWithoutResponse(
     const Message* message,
@@ skipping 160 matching lines @@
                                ValidationContext* validation_context) {
   if (validation_context->ClaimHandle(input))
     return true;
 
   ReportValidationError(validation_context, VALIDATION_ERROR_ILLEGAL_HANDLE);
   return false;
 }
 
 }  // namespace internal
 }  // namespace mojo