Third try at landing gRPC refactoring. Previous issue failed on the waterfall

components/grpc_support/test/get_stream_engine.cc

Index: components/grpc_support/test/get_stream_engine.cc
diff --git a/components/grpc_support/test/get_stream_engine.cc b/components/grpc_support/test/get_stream_engine.cc
new file mode 100644
index 0000000000000000000000000000000000000000..f665130152246f21f904976ad285462179c4ebc0
--- /dev/null
+++ b/components/grpc_support/test/get_stream_engine.cc
@@ -0,0 +1,131 @@
+// 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/lazy_instance.h"
+#include "base/macros.h"
+#include "base/memory/ptr_util.h"
+#include "base/memory/ref_counted.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/stringprintf.h"
+#include "base/threading/thread.h"
+#include "components/grpc_support/include/bidirectional_stream_c.h"
+#include "components/grpc_support/test/quic_test_server.h"
+#include "net/base/host_port_pair.h"
+#include "net/cert/mock_cert_verifier.h"
+#include "net/dns/mapped_host_resolver.h"
+#include "net/dns/mock_host_resolver.h"
+#include "net/http/http_server_properties_impl.h"
+#include "net/url_request/url_request_test_util.h"
+
+namespace grpc_support {
+namespace {
+
+// URLRequestContextGetter for BidirectionalStreamTest. This is used instead of
+// net::TestURLRequestContextGetter because the URLRequestContext needs to be
+// created on the test_io_thread_ for the test, and TestURLRequestContextGetter
+// does not allow for lazy instantiation of the URLRequestContext if additional
+// setup is required.
+class BidirectionalStreamTestURLRequestContextGetter
+    : public net::URLRequestContextGetter {
+ public:
+  BidirectionalStreamTestURLRequestContextGetter(
+      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner)
+      : task_runner_(task_runner) {}
+
+  net::URLRequestContext* GetURLRequestContext() override {
+    if (!request_context_.get()) {
+      request_context_.reset(
+          new net::TestURLRequestContext(true /* delay_initialization */));
+      auto mock_host_resolver = base::MakeUnique<net::MockHostResolver>();
+      host_resolver_.reset(
+          new net::MappedHostResolver(std::move(mock_host_resolver)));
+      UpdateHostResolverRules();
+      mock_cert_verifier_.reset(new net::MockCertVerifier());
+      mock_cert_verifier_->set_default_result(net::OK);
+      server_properties_.reset(new net::HttpServerPropertiesImpl());
+
+      // Need to enable QUIC for the test server.
+      auto params = base::MakeUnique<net::HttpNetworkSession::Params>();
+      params->enable_quic = true;
+      params->enable_http2 = true;
+      net::AlternativeService alternative_service(net::AlternateProtocol::QUIC,
+                                                  "", 443);
+      url::SchemeHostPort quic_hint_server("https", kTestServerHost, 443);
+      server_properties_->SetAlternativeService(
+          quic_hint_server, alternative_service, base::Time::Max());
+      params->quic_host_whitelist.insert(kTestServerHost);
+
+      request_context_->set_cert_verifier(mock_cert_verifier_.get());
+      request_context_->set_host_resolver(host_resolver_.get());
+      request_context_->set_http_server_properties(server_properties_.get());
+      request_context_->set_http_network_session_params(std::move(params));
+
+      request_context_->Init();
+    }
+    return request_context_.get();
+  }
+
+  scoped_refptr<base::SingleThreadTaskRunner> GetNetworkTaskRunner()
+      const override {
+    return task_runner_;
+  }
+
+  void SetTestServerPort(int port) {
+    test_server_port_ = port;
+    UpdateHostResolverRules();
+  }
+
+ private:
+  void UpdateHostResolverRules() {
+    if (!host_resolver_)
+      return;
+    host_resolver_->SetRulesFromString(
+        base::StringPrintf("MAP notfound.example.com ~NOTFOUND,"
+                           "MAP test.example.com 127.0.0.1:%d",
+                           test_server_port_));
+  }
+  ~BidirectionalStreamTestURLRequestContextGetter() override {}
+
+  int test_server_port_;
+  std::unique_ptr<net::HttpServerProperties> server_properties_;
+  std::unique_ptr<net::MockCertVerifier> mock_cert_verifier_;
+  std::unique_ptr<net::MappedHostResolver> host_resolver_;
+  std::unique_ptr<net::TestURLRequestContext> request_context_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(BidirectionalStreamTestURLRequestContextGetter);
+};
+
+base::LazyInstance<
+    scoped_refptr<BidirectionalStreamTestURLRequestContextGetter>>
+    ::Leaky g_request_context_getter_ = LAZY_INSTANCE_INITIALIZER;
+bool g_initialized_ = false;
+
+}  // namespace
+
+void CreateRequestContextGetterIfNecessary() {
+  if (!g_initialized_) {
+    g_initialized_ = true;
+    static base::Thread* test_io_thread_ =
+        new base::Thread("grpc_support_test_io_thread");
+    base::Thread::Options options;
+    options.message_loop_type = base::MessageLoop::TYPE_IO;
+    bool started = test_io_thread_->StartWithOptions(options);
+    DCHECK(started);
+
+    g_request_context_getter_.Get() =
+        new BidirectionalStreamTestURLRequestContextGetter(
+            test_io_thread_->task_runner());
+  }
+}
+
+stream_engine* GetTestStreamEngine(int port) {
+  CreateRequestContextGetterIfNecessary();
+  g_request_context_getter_.Get()->SetTestServerPort(port);
+  static stream_engine engine;
+  engine.obj = g_request_context_getter_.Get().get();
+  return &engine;
+}
+
+}  // namespace grpc_support