Update to Chromium version 70.0.3538.0 (#587811)

Known issues:
- The CefLoadCRLSetsFile function needs to be re-implemented (see issue #2497).
- Linux: GTK2 support has been removed. The cefclient sample needs to be updated
  to use GTK3 (see issue #2014).

libcef/browser/extensions/extensions_browser_api_provider.cc

@@ -0,0 +1,29 @@
+// Copyright 2018 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 "libcef/browser/extensions/chrome_api_registration.h"
+#include "libcef/browser/extensions/extensions_browser_api_provider.h"
+
+//#include "cef/libcef/browser/extensions/api/generated_api_registration.h"
+#include "extensions/browser/api/generated_api_registration.h"
+
+namespace extensions {
+
+CefExtensionsBrowserAPIProvider::CefExtensionsBrowserAPIProvider() =
+    default;
+CefExtensionsBrowserAPIProvider::~CefExtensionsBrowserAPIProvider() =
+    default;
+
+void CefExtensionsBrowserAPIProvider::RegisterExtensionFunctions(
+    ExtensionFunctionRegistry* registry) {
+  // CEF-only APIs.
+  // TODO(cef): Enable if/when CEF exposes its own Mojo APIs. See
+  // libcef/common/extensions/api/README.txt for details.
+  // api::cef::CefGeneratedFunctionRegistry::RegisterAll(registry);
+
+  // Chrome APIs whitelisted by CEF.
+  api::cef::ChromeFunctionRegistry::RegisterAll(registry);
+}
+
+}  // namespace extensions