Enables specifying mojo url mapping on command line

mojo/shell/mojo_url_resolver_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/shell/mojo_url_resolver.h"
+
+#include "base/logging.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace mojo {
+namespace shell {
+namespace test {
+namespace {
+
+typedef testing::Test MojoURLResolverTest;
+
+TEST_F(MojoURLResolverTest, MojoURLsFallThrough) {
+  MojoURLResolver resolver;
+  resolver.AddCustomMapping(GURL("mojo:test"), GURL("mojo:foo"));
+  const GURL base_url("file:/base");
+  resolver.SetBaseURL(base_url);
+  const std::string resolved(resolver.Resolve(GURL("mojo:test")).spec());
+  // Resolved must start with |base_url|.
+  EXPECT_EQ(base_url.spec(), resolved.substr(0, base_url.spec().size()));
+  // And must contain foo (which is what test mapped to.
+  EXPECT_NE(std::string::npos, resolved.find("foo"));
+}
+
+}  // namespace
+}  // namespace test
+}  // namespace shell
+}  // namespace mojo