Implement HiDPI support in Pepper dev interface

ppapi/tests/test_graphics_2d.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_GRAPHICS_2D_H_
 #define PPAPI_TESTS_TEST_GRAPHICS_2D_H_
 
 #include <string>
 
 #include "ppapi/c/pp_stdint.h"
@@ skipping 60 matching lines @@
 
   std::string TestInvalidResource();
   std::string TestInvalidSize();
   std::string TestHumongous();
   std::string TestInitToZero();
   std::string TestDescribe();
   std::string TestPaint();
   std::string TestScroll();
   std::string TestReplace();
   std::string TestFlush();
+  std::string TestDev();
 
   // Used by the tests that access the C API directly.
   const PPB_Graphics2D* graphics_2d_interface_;
   const PPB_ImageData* image_data_interface_;
 };
 
 #endif  // PPAPI_TESTS_TEST_GRAPHICS_2D_H_