Fix missing call to destroy library in embedder test.

testing/embedder_test.cpp

 // Copyright (c) 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.
 
 #include "embedder_test.h"
 
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ skipping 177 matching lines @@
     UNSUPPORT_INFO unsuppored_info;
     memset(&unsuppored_info, '\0', sizeof(unsuppored_info));
     unsuppored_info.version = 1;
     unsuppored_info.FSDK_UnSupport_Handler = Unsupported_Handler;
     FSDK_SetUnSpObjProcessHandler(&unsuppored_info);
   }
 
 void EmbedderTest::TearDown() {
   FPDF_CloseDocument(document_);
   FPDFAvail_Destroy(avail_);
+  FPDF_DestroyLibrary();
   if (loader_) {
     delete loader_;
   }
   if (file_contents_) {
     free(file_contents_);
   }
 }
 
 bool EmbedderTest::OpenDocument(const std::string& filename) {
   file_contents_ = GetFileContents(filename.c_str(), &file_length_);
@@ skipping 88 matching lines @@
   FPDF_RenderPageBitmap(bitmap, page, 0, 0, width, height, 0, 0);
   FPDF_FFLDraw(form, bitmap, page, 0, 0, width, height, 0, 0);
   return bitmap;
 }
 
 void EmbedderTest::UnloadPage(FPDF_PAGE page, FPDF_FORMHANDLE form) {
   FORM_DoPageAAction(page, form, FPDFPAGE_AACTION_CLOSE);
   FORM_OnBeforeClosePage(page, form);
   FPDF_ClosePage(page);
 }