Remove requirement that mojo::Environment be instantiated.

mojo/public/cpp/bindings/tests/request_response_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/public/cpp/bindings/binding.h"
-#include "mojo/public/cpp/environment/environment.h"
 #include "mojo/public/cpp/test_support/test_utils.h"
 #include "mojo/public/cpp/utility/run_loop.h"
 #include "mojo/public/interfaces/bindings/tests/sample_import.mojom.h"
 #include "mojo/public/interfaces/bindings/tests/sample_interfaces.mojom.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace mojo {
 namespace test {
 namespace {
 
@@ skipping 66 matching lines @@
   std::string text_;
 };
 
 class RequestResponseTest : public testing::Test {
  public:
   ~RequestResponseTest() override { loop_.RunUntilIdle(); }
 
   void PumpMessages() { loop_.RunUntilIdle(); }
 
  private:
-  Environment env_;
   RunLoop loop_;
 };
 
 TEST_F(RequestResponseTest, EchoString) {
   sample::ProviderPtr provider;
   ProviderImpl provider_impl(GetProxy(&provider));
 
   std::string buf;
   provider->EchoString(String::From("hello"), StringRecorder(&buf));
 
@@ skipping 39 matching lines @@
   provider->EchoEnum(sample::Enum::VALUE, EnumRecorder(&value));
 
   PumpMessages();
 
   EXPECT_EQ(sample::Enum::VALUE, value);
 }
 
 }  // namespace
 }  // namespace test
 }  // namespace mojo