Avoid two targeting phases in aura client-lib and EventProcessor.

ui/aura/test/test_window_targeter.cc

+// 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 "ui/aura/test/test_window_targeter.h"
+
+namespace aura {
+namespace test {
+
+TestWindowTargeter::TestWindowTargeter() {}
+
+TestWindowTargeter::~TestWindowTargeter() {}
+
+ui::EventTarget* TestWindowTargeter::FindTargetForEvent(ui::EventTarget* root,
+                                                        ui::Event* event) {
+  return root;
+}
+
+ui::EventTarget* TestWindowTargeter::FindNextBestTarget(
+    ui::EventTarget* previous_target,
+    ui::Event* event) {
+  return previous_target;
+}
+
+}  // namespace test
+}  // namespace aura