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

ui/events/event_processor_unittest.cc

 // Copyright (c) 2013 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 <utility>
 #include <vector>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 20 matching lines @@
  protected:
   // testing::Test:
   void SetUp() override {
     processor_.SetRoot(base::MakeUnique<TestEventTarget>());
     processor_.Reset();
     root()->SetEventTargeter(
         base::MakeUnique<TestEventTargeter>(root(), false));
   }
 
   TestEventTarget* root() {
-    return static_cast<TestEventTarget*>(processor_.GetRootTarget());
+    return static_cast<TestEventTarget*>(processor_.GetRoot());
   }
 
   TestEventProcessor* processor() {
     return &processor_;
   }
 
   void DispatchEvent(Event* event) {
     processor_.OnEventFromSource(event);
   }
 
@@ skipping 316 matching lines @@
   DispatchEvent(&mouse);
 
   std::string expected[] = { "PreR", "PreC", "PreG", "G", "PostG", "PostC",
       "PostR", "PreR", "PreC", "C", "PostC", "PostR", "PreR", "R", "PostR" };
   EXPECT_EQ(std::vector<std::string>(
       expected, expected + arraysize(expected)), recorder);
 }
 
 }  // namespace test
 }  // namespace ui