Add GetSequenceNumber function to PPB_Flash_Clipboard

ppapi/tests/test_flash_clipboard.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 PPAPI_TESTS_TEST_FLASH_CLIPBOARD_H_
 #define PPAPI_TESTS_TEST_FLASH_CLIPBOARD_H_
 
 #include <string>
 
 #include "ppapi/c/private/ppb_flash_clipboard.h"
 #include "ppapi/tests/test_case.h"
 #include "ppapi/tests/test_utils.h"
 
 class TestFlashClipboard : public TestCase {
  public:
   explicit TestFlashClipboard(TestingInstance* instance);
 
   // TestCase implementation.
   virtual void RunTests(const std::string& filter);
 
  private:
   // Helpers.
   bool ReadStringVar(uint32_t format, std::string* result);
   bool WriteStringVar(uint32_t format, const std::string& text);
   bool IsFormatAvailableMatches(uint32_t format, bool expected);
   bool ReadPlainTextMatches(const std::string& expected);
   bool ReadHTMLMatches(const std::string& expected);
+  uint64_t GetSequenceNumber(uint64_t last_sequence_number);
 
   // Tests.
   std::string TestReadWritePlainText();
   std::string TestReadWriteHTML();
   std::string TestReadWriteRTF();
   std::string TestReadWriteMultipleFormats();
   std::string TestReadWriteCustomData();
   std::string TestClear();
   std::string TestInvalidFormat();
   std::string TestRegisterCustomFormat();
+  std::string TestGetSequenceNumber();
 };
 
 #endif  // PAPPI_TESTS_TEST_FLASH_FULLSCREEN_H_