Fix wrong header guards found by clang's new Wheader-guard.

ppapi/tests/test_flash_file.h

 // 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.
 
-#ifndef PAPPI_TESTS_TEST_FLASH_FILE_H_
+#ifndef PPAPI_TESTS_TEST_FLASH_FILE_H_
 #define PPAPI_TESTS_TEST_FLASH_FILE_H_
 
 #include <string>
 
 #include "ppapi/tests/test_case.h"
 
 class TestFlashFile: public TestCase {
  public:
   explicit TestFlashFile(TestingInstance* instance);
   virtual ~TestFlashFile();
@@ skipping 17 matching lines @@
   // TODO(raymes): Add these when we can test file chooser properly.
   // std::string TestOpenFileRef();
   // std::string TestQueryFileRef();
 
   // Gets the number of files and directories under the module-local root
   // directory.
   std::string GetItemCountUnderModuleLocalRoot(size_t* item_count);
 };
 
 #endif  // PPAPI_TESTS_TEST_FLASH_FILE_H_