Validate MessageHeader before using

mojo/common/test/test_support_impl.h

 // Copyright 2014 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_COMMON_TEST_TEST_SUPPORT_IMPL_H_
 #define MOJO_COMMON_TEST_TEST_SUPPORT_IMPL_H_
 
 #include "base/macros.h"
 #include "mojo/public/tests/test_support_private.h"
 
 namespace mojo {
 namespace test {
 
 class TestSupportImpl : public TestSupport {
  public:
   TestSupportImpl();
   virtual ~TestSupportImpl();
 
   virtual void LogPerfResult(const char* test_name,
                              double value,
                              const char* units) OVERRIDE;
+  virtual FILE* OpenSourceRootRelativeFile(const char* relative_path) OVERRIDE;
+  virtual char** EnumerateSourceRootRelativeDirectory(const char* relative_path)
+      OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(TestSupportImpl);
 };
 
 }  // namespace test
 }  // namespace mojo
 
 #endif  // MOJO_COMMON_TEST_TEST_SUPPORT_IMPL_H_