Add a new group policy to disable safe browsing for files downloaded from trusted sources.

chrome/browser/download/trusted_sources_manager_win.cc

Index: chrome/browser/download/trusted_sources_manager_win.cc
diff --git a/chrome/browser/download/trusted_sources_manager_win.cc b/chrome/browser/download/trusted_sources_manager_win.cc
new file mode 100644
index 0000000000000000000000000000000000000000..88bcf710a021871269703ec565b76809cbc5633f
--- /dev/null
+++ b/chrome/browser/download/trusted_sources_manager_win.cc
@@ -0,0 +1,54 @@
+// Copyright (c) 2017 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/download/trusted_sources_manager.h"
+
+#include <urlmon.h>
+
+#include "base/logging.h"
+#include "base/strings/string_util.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/win/scoped_comptr.h"
+#include "url/gurl.h"
+
+namespace {
+
+class TrustedSourcesManagerWin : public TrustedSourcesManager {
+ public:
+  TrustedSourcesManagerWin();
+  ~TrustedSourcesManagerWin() override;
+
+  // TrustedSourcesManager methods:
+  bool IsFromTrustedSource(const GURL& url) const override;
+};
+
+TrustedSourcesManagerWin::TrustedSourcesManagerWin() = default;
+TrustedSourcesManagerWin::~TrustedSourcesManagerWin() = default;
+
+bool TrustedSourcesManagerWin::IsFromTrustedSource(const GURL& url) const {
+  base::win::ScopedComPtr<IInternetSecurityManager> security_manager;
+  HRESULT hr = ::CoInternetCreateSecurityManager(
+      NULL, security_manager.GetAddressOf(), NULL);
+  // URLZONE_LOCAL_MACHINE 0
+  // URLZONE_INTRANET      1
+  // URLZONE_TRUSTED       2
+  // URLZONE_INTERNET      3
+  // URLZONE_UNTRUSTED     4
+  DWORD zone = 0;
+  base::string16 url16 = base::ASCIIToUTF16(url.spec());
+  hr = security_manager->MapUrlToZone(url16.c_str(), &zone, 0);
+  if (FAILED(hr)) {
+    LOG(ERROR) << "security_manager->MapUrlToZone failed with hr: " << std::hex
+               << hr;
+    return false;
+  }
+  return zone <= static_cast<DWORD>(URLZONE_TRUSTED);
+}
+
+}  // namespace
+
+// static
+TrustedSourcesManager* TrustedSourcesManager::Create() {
+  return new TrustedSourcesManagerWin;
+}