Check that the PNaCl cache hash is truly derived from the bitcode content.

ppapi/native_client/src/trusted/plugin/plugin_error.h

 /*
  * Copyright (c) 2011 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.
  */
 
 /*
  * Error codes and data structures used to report errors when loading a nexe.
  */
 
@@ skipping 80 matching lines @@
   ERROR_PNACL_LLC_SETUP = 63,
   ERROR_PNACL_LD_SETUP = 64,
   ERROR_PNACL_LLC_INTERNAL = 65,
   ERROR_PNACL_LD_INTERNAL = 66,
   ERROR_PNACL_CREATE_TEMP = 67,
   // Remove this next code when pnacl is no longer behind a flag (when we
   // remove the --enable-pnacl flag).
   ERROR_PNACL_NOT_ENABLED = 68,
   ERROR_MANIFEST_NOACCESS_URL = 69,
   ERROR_NEXE_NOACCESS_URL = 70,
+  ERROR_PNACL_CACHE_HASH_MISMATCH = 71,
   // If you add a code, read the enum comment above on how to update histograms.
   ERROR_MAX
 };
 
 class ErrorInfo {
  public:
   ErrorInfo() {
     Reset();
   }
 
@@ skipping 20 matching lines @@
 
  private:
   PluginErrorCode error_code_;
   std::string message_;
   NACL_DISALLOW_COPY_AND_ASSIGN(ErrorInfo);
 };
 
 }  // namespace plugin
 
 #endif  // NATIVE_CLIENT_SRC_TRUSTED_PLUGIN_PLUGIN_ERROR_H