Support default values for arrays of POD data types in mojom.

mojo/public/tests/bindings/sample_service_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 <algorithm>
 #include <ostream>
 #include <string>
 
 #include "mojo/public/environment/environment.h"
 #include "mojom/sample_service.h"
@@ skipping 303 matching lines @@
   SimpleMessageReceiver receiver;
   mojo::AllocationScope scope;
 
   Bar bar = Bar::Builder().Finish();
   EXPECT_EQ(255, bar.alpha());
 
   Foo foo = Foo::Builder().Finish();
   ASSERT_FALSE(foo.name().is_null());
   EXPECT_EQ("Fooby", foo.name().To<std::string>());
   EXPECT_TRUE(foo.a());
+  EXPECT_EQ(3u, foo.data().size());
+  EXPECT_EQ(1, foo.data()[0]);
+  EXPECT_EQ(2, foo.data()[1]);
+  EXPECT_EQ(3, foo.data()[2]);
 }
 
 }  // namespace sample