Return unique_ptrs from test_support functions

samples/pdfium_test.cc

 // Copyright (c) 2010 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.
 
 #include <limits.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include <list>
@@ skipping 572 matching lines @@
   memset(&unsuppored_info, '\0', sizeof(unsuppored_info));
   unsuppored_info.version = 1;
   unsuppored_info.FSDK_UnSupport_Handler = ExampleUnsupportedHandler;
 
   FSDK_SetUnSpObjProcessHandler(&unsuppored_info);
 
   while (!files.empty()) {
     std::string filename = files.front();
     files.pop_front();
     size_t file_length = 0;
-    char* file_contents = GetFileContents(filename.c_str(), &file_length);
-    if (!file_contents)
-      continue;
-    RenderPdf(filename, file_contents, file_length, options);
-    free(file_contents);
+    std::unique_ptr<char, pdfium::FreeDeleter> file_contents =
+        GetFileContents(filename.c_str(), &file_length);
+    if (file_contents)
+      RenderPdf(filename, file_contents.get(), file_length, options);
   }
 
   FPDF_DestroyLibrary();
 #ifdef PDF_ENABLE_V8
   v8::V8::ShutdownPlatform();
   delete platform;
 #endif  // PDF_ENABLE_V8
 
   return 0;
 }