Create a RegisterViewAssociate method in ViewManager

services/ui/view_manager/tests/view_manager_test_base.h

+// 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 "base/bind.h"
+#include "mojo/public/cpp/application/application_test_base.h"
+
+namespace view_manager {
+namespace test {
+
+const base::TimeDelta kDefaultMessageDelay =

[jeffbrown, 2016/05/11 23:44:16]

You can move this into the .cc file.  Also, we don't allow static initialization
of complex types, so you'll have to declare a simple integer constant for the
number of milliseconds instead.  (Could be fixed if base::TimeDelta's methods
were constexpr.)

+    base::TimeDelta::FromMilliseconds(4);
+
+// Run message loop until condition is true (timeout after 50*4ms = 200ms)

[jeffbrown, 2016/05/11 23:44:16]

I suspect this is why the test is flaky.  We're actually starting services and a
cold start could be pretty slow.  I'd suggest just looping indefinitely.

Also, consider passing a lambda instead of using a macro.

[mikejurka, 2016/05/16 23:35:18]

You mean a lambda for the "while" condition? I feel like that'd be quite
verbose, and this is just for tests.

+#define KICK_MESSAGE_LOOP_WHILE(x)    \
+  for (int i = 0; x && i < 50; i++) { \
+    KickMessageLoop();                \
+  }
+
+class ViewManagerTestBase : public mojo::test::ApplicationTestBase {
+ public:
+  ViewManagerTestBase();
+  ~ViewManagerTestBase() override;
+
+  void SetUp() override;
+
+  void QuitMessageLoopCallback();

[jeffbrown, 2016/05/11 23:44:16]

This doesn't need to be public, can be private.

[mikejurka, 2016/05/16 23:35:18]

Done.

+
+  void KickMessageLoop();
+
+ protected:
+  base::Closure quit_message_loop_callback_;
+  base::WeakPtrFactory<ViewManagerTestBase> weak_factory_;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(ViewManagerTestBase);
+};
+
+}  // namespace test
+}  // namespace view_manager