[Downloads] Consolidate MOTW annotation APIs into a single API.

content/browser/download/quarantine.h

Index: content/browser/download/quarantine.h
diff --git a/content/browser/download/quarantine.h b/content/browser/download/quarantine.h
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+// Copyright 2016 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 CONTENT_BROWSER_DOWNLOAD_QUARANTINE_H_
+#define CONTENT_BROWSER_DOWNLOAD_QUARANTINE_H_
+
+#include <string>
+
+#include "content/common/content_export.h"
+
+class GURL;
+
+namespace base {
+class FilePath;
+}
+
+namespace content {
+
+// Return value for QuarantineFile.
+enum class QuarantineFileResult {
+  OK,             // Success.
+  ACCESS_DENIED,  // Access to the file was denied. The safety of the file could
+                  // not be determined.
+  BLOCKED_BY_POLICY,  // Downloads from |source_url| are not allowed by policy.
+                      // The file has been deleted.
+  ANNOTATION_FAILED,  // Unable to write the mark-of-the-web or otherwise
+                      // annotate the file as being downloaded from
+                      // |source_url|.
+  FILE_MISSING,       // |file| does not name a valid file.
+  SECURITY_CHECK_FAILED,  // An unknown error occurred while checking |file|.
+                          // The file may have been deleted.
+  VIRUS_INFECTED  // |file| was found to be infected by a virus and was deleted.
+};
+
+// Quarantine a file that was downloaded from the internet.
+//
+// Ensures that |file| is handled as safely as possible given that it was
+// downloaded from |source_url|. The details of how a downloaded file is handled
+// are platform dependent. Please refer to the individual quarantine_<os>
+// implementation.
+//
+// This function should be called for all files downloaded from the internet and
+// placed in a manner discoverable by the user, or exposed to an external
+// application. Furthermore, it should be called:
+//
+// * **AFTER** all the data has been written to the file. On Windows, registered
+//   anti-virus products will be invoked for scanning the contents of the file.
+//   Hence it's important to have the final contents of the file be available at
+//   the point at which this function is called.
+//
+//   Exception: Zero-length files will be handled solely on the basis of the
+//   |source_url| and the file type. This exception accommodates situations
+//   where the file contents cannot be determined before it is made visible to
+//   an external application.
+//
+// * **AFTER** the file has been renamed to its final name. The file type is
+//   significant and is derived from the filename.
+//
+// * **BEFORE** the file is made visible to an external application or the user.
+//   Security checks and mark-of-the-web annotations must be made prior to
+//   exposing the file externally.
+//
+// Note that it is possible for this method to take a long time to complete
+// (several seconds or more). In addition to blocking during this time, this
+// delay also introduces a window during which a browser shutdown may leave the
+// downloaded file unannotated.
+//
+// Parameters:
+//   |file| : Final name of the file.
+//   |source_url|: URL from which the file content was downloaded.
+//   |referrer_url|: Referring URL.
+//   |client_guid|: Only used on Windows. Identifies the client application
+//     that downloaded the file.
+CONTENT_EXPORT QuarantineFileResult
+QuarantineFile(const base::FilePath& file,
+               const GURL& source_url,
+               const GURL& referrer_url,
+               const std::string& client_guid);
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_DOWNLOAD_QUARANTINE_H_