Out-of-process file patcher: DCHECK the files in the utility process

chrome/utility/chrome_content_utility_client.cc

 // 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.
 
 #include "chrome/utility/chrome_content_utility_client.h"
 
 #include <stddef.h>
 #include <utility>
 #include <vector>
 
@@ skipping 66 matching lines @@
     mojo::MakeStrongBinding(base::MakeUnique<FilePatcherImpl>(),
                             std::move(request));
   }
 
  private:
   // chrome::mojom::FilePatcher:
   void PatchFileBsdiff(base::File input_file,
                        base::File patch_file,
                        base::File output_file,
                        const PatchFileBsdiffCallback& callback) override {
+    DCHECK(input_file.IsValid());
+    DCHECK(patch_file.IsValid());
+    DCHECK(output_file.IsValid());
+
     const int patch_result_status = bsdiff::ApplyBinaryPatch(
         std::move(input_file), std::move(patch_file), std::move(output_file));
     callback.Run(patch_result_status);
   }
 
   void PatchFileCourgette(base::File input_file,
                           base::File patch_file,
                           base::File output_file,
                           const PatchFileCourgetteCallback& callback) override {
+    DCHECK(input_file.IsValid());
+    DCHECK(patch_file.IsValid());
+    DCHECK(output_file.IsValid());
+
     const int patch_result_status = courgette::ApplyEnsemblePatch(
         std::move(input_file), std::move(patch_file), std::move(output_file));
     callback.Run(patch_result_status);
   }
 
   DISALLOW_COPY_AND_ASSIGN(FilePatcherImpl);
 };
 
 #if defined(OS_CHROMEOS)
 class ZipFileCreatorImpl : public chrome::mojom::ZipFileCreator {
@@ skipping 191 matching lines @@
   safe_browsing::dmg::AnalyzeDMGFile(
       IPC::PlatformFileForTransitToFile(dmg_file), &results);
   content::UtilityThread::Get()->Send(
       new ChromeUtilityHostMsg_AnalyzeDmgFileForDownloadProtection_Finished(
           results));
   content::UtilityThread::Get()->ReleaseProcessIfNeeded();
 }
 #endif  // defined(OS_MACOSX)
 
 #endif  // defined(FULL_SAFE_BROWSING)