Collect some histograms about signed binary downloads.

chrome/browser/safe_browsing/signature_util_win.cc

+// Copyright (c) 2011 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/browser/safe_browsing/signature_util.h"
+
+#include <windows.h>
+#include <wincrypt.h>
+#include "base/file_path.h"
+
+namespace safe_browsing {
+namespace signature_util {
+
+bool IsSigned(const FilePath& file_path) {
+  // Get message handle and store handle from the signed file.
+  BOOL result = CryptQueryObject(CERT_QUERY_OBJECT_FILE,
+                                 file_path.value().c_str(),
+                                 CERT_QUERY_CONTENT_FLAG_PKCS7_SIGNED_EMBED,
+                                 CERT_QUERY_FORMAT_FLAG_BINARY,
+                                 0,      // flags
+                                 NULL,   // encoding
+                                 NULL,   // content type
+                                 NULL,   // format type
+                                 NULL,   // HCERTSTORE
+                                 NULL,   // HCRYPTMSG
+                                 NULL);  // context
+  return result == TRUE;
+}
+
+}  // namespace signature_util
+}  // namespace safe_browsing