Cleanup page when unloading in embedder tests

testing/embedder_test.h

 // Copyright 2015 PDFium 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 TESTING_EMBEDDER_TEST_H_
 #define TESTING_EMBEDDER_TEST_H_
 
 #include <map>
 #include <memory>
 #include <string>
@@ skipping 106 matching lines @@
   FPDF_FILEACCESS file_access_;
   FX_FILEAVAIL file_avail_;
 #ifdef PDF_ENABLE_V8
   v8::Platform* platform_;
 #endif  // PDF_ENABLE_V8
   void* external_isolate_;
   TestLoader* loader_;
   size_t file_length_;
   std::unique_ptr<char, pdfium::FreeDeleter> file_contents_;
   std::map<int, FPDF_PAGE> page_map_;
+  std::map<FPDF_PAGE, int> page_reverse_map_;
 
  private:
   static void UnsupportedHandlerTrampoline(UNSUPPORT_INFO*, int type);
   static int AlertTrampoline(IPDF_JSPLATFORM* plaform,
                              FPDF_WIDESTRING message,
                              FPDF_WIDESTRING title,
                              int type,
                              int icon);
   static int SetTimerTrampoline(FPDF_FORMFILLINFO* info,
                                 int msecs,
                                 TimerCallback fn);
   static void KillTimerTrampoline(FPDF_FORMFILLINFO* info, int id);
   static FPDF_PAGE GetPageTrampoline(FPDF_FORMFILLINFO* info,
                                      FPDF_DOCUMENT document,
                                      int page_index);
 };
 
 #endif  // TESTING_EMBEDDER_TEST_H_