Split FaviconService and FaviconServiceImpl.

components/favicon/core/test/mock_favicon_service.cc

Index: components/favicon/core/test/mock_favicon_service.cc
diff --git a/components/favicon/core/test/mock_favicon_service.cc b/components/favicon/core/test/mock_favicon_service.cc
new file mode 100644
index 0000000000000000000000000000000000000000..a0a57ccc00f37a3109b965ec307a5672acb522b2
--- /dev/null
+++ b/components/favicon/core/test/mock_favicon_service.cc
@@ -0,0 +1,13 @@
+// Copyright 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 "components/favicon/core/test/mock_favicon_service.h"
+
+namespace favicon {
+
+MockFaviconService::MockFaviconService() = default;
+
+MockFaviconService::~MockFaviconService() = default;
+
+}  // namespace favicon