Fix invalid expectation in unittest.

mojo/services/public/cpp/view_manager/tests/view_manager_unittest.cc

 // Copyright 2014 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 "mojo/services/public/cpp/view_manager/view_manager.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "mojo/services/public/cpp/view_manager/lib/view_manager_private.h"
 #include "mojo/services/public/cpp/view_manager/lib/view_manager_synchronizer.h"
@@ skipping 606 matching lines @@
 
   ViewTreeNode* node1_2 = view_manager_2()->GetNodeById(node1->id());
   node1_2->SetBounds(gfx::Rect(1024, 768));
   // Bounds change should have been rejected.
   EXPECT_EQ(node1->bounds(), node1_2->bounds());
 }
 
 // Verifies that a node can only be destroyed by the connection that created it.
 TEST_F(ViewManagerTest, DestroySecurity) {
   ViewTreeNode* node1 = CreateNodeInParent(view_manager_1()->tree());
-  WaitForTreeSizeToMatch(view_manager_2()->tree(), 3);
+  WaitForTreeSizeToMatch(view_manager_2()->tree(), 2);
 
   ViewTreeNode* node1_2 = view_manager_2()->GetNodeById(node1->id());
   NodeTracker tracker2(node1_2);
   node1_2->Destroy();
   // Node should not have been destroyed.
   EXPECT_TRUE(tracker2.is_valid());
 
   NodeTracker tracker1(node1);
   node1->Destroy();
   EXPECT_FALSE(tracker1.is_valid());
 }
 
 }  // namespace view_manager
 }  // namespace mojo