Extract WebViewClient implementation out of WebTestProxyBase.

components/test_runner/web_frame_test_proxy.cc

Index: components/test_runner/web_frame_test_proxy.cc
diff --git a/components/test_runner/web_frame_test_proxy.cc b/components/test_runner/web_frame_test_proxy.cc
new file mode 100644
index 0000000000000000000000000000000000000000..6934090f5dad6db77553ca395daa18aa965a2f63
--- /dev/null
+++ b/components/test_runner/web_frame_test_proxy.cc
@@ -0,0 +1,12 @@
+// 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.
+
+#include "components/test_runner/web_frame_test_proxy.h"
+
+namespace test_runner {
+
+WebFrameTestProxyBase::WebFrameTestProxyBase() {}
+WebFrameTestProxyBase::~WebFrameTestProxyBase() {}
+
+}  // namespace test_runner