[cronet] Add support for building Cronet for Linux, Mac & Fuchsia.

This adds supports for building Cronet as a native shared library which can
be used through the C API generated from cronet.idl.

This is based on jamesr@'s work-in-progress to bring up the Cronet
library for Fuchsia:
https://chromium-review.googlesource.com/c/chromium/src/+/896389

Bug: 808075
Cq-Include-Trybots: master.tryserver.chromium.android:android_cronet_tester;master.tryserver.chromium.mac:ios-simulator-cronet
Change-Id: I598a8d1ca049e8c166e57546b7bdbf53e4659831
Reviewed-on: https://chromium-review.googlesource.com/914805
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: Matt Menke <mmenke@chromium.org>
Reviewed-by: Andrei Kapishnikov <kapishnikov@chromium.org>
Reviewed-by: Scott Graham <scottmg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#537527}

BUILD.gn

@@ -182,6 +182,14 @@ group("gn_all") {
     ]
   }
 
+  # TODO(https://crbug.com/812268): Fix Windows build, and enable it.
+  if (!is_ios && !is_android && !is_win) {
+    deps += [
+      "//components/cronet:cronet_tests",
+      "//components/cronet:cronet_unittests",
+    ]
+  }
+
   if (!is_ios && !is_fuchsia) {
     deps += [
       "//chrome/test:telemetry_perf_unittests",

components/cronet/BUILD.gn

@@ -65,3 +65,52 @@ source_set("cronet_common_unittests") {
     "url_request_context_config_unittest.cc",
   ]
 }
+
+# For platforms on which the native Cronet library is used, build the library,
+# a cronet_tests binary that exercises it, and a unit-tests binary.
+# Android and iOS have their own platform-specific rules to build Cronet.
+# TODO(https://crbug.com/812268): Fix Windows build, and enable it.
+if (!is_ios && !is_android && !is_win) {
+  shared_library("cronet") {
+    deps = [
+      "//base",
+
+      # Explicitly add the exe_and_shlib_deps, otherwise the library will fail
+      # to link in component builds, due to missing libc++ symbols.
+      "//build/config:exe_and_shlib_deps",
+      "//components/cronet:cronet_common",
+      "//components/cronet/native:cronet_native_impl",
+      "//net",
+    ]
+
+    sources = [
+      "cronet_global_state_stubs.cc",
+    ]
+  }
+
+  test("cronet_tests") {
+    testonly = true
+
+    deps = [
+      ":cronet",
+      "//components/cronet/native/test:cronet_native_tests",
+      "//testing/gtest:gtest_main",
+    ]
+  }
+
+  test("cronet_unittests") {
+    testonly = true
+
+    deps = [
+      ":cronet_common",
+      ":cronet_common_unittests",
+      "//base",
+      "//components/cronet/native:cronet_native_unittests",
+      "//net",
+    ]
+
+    sources = [
+      "cronet_global_state_stubs.cc",
+    ]
+  }
+}

components/cronet/cronet_global_state.h

@@ -18,8 +18,8 @@ class ProxyResolutionService;
 
 namespace cronet {
 
-// Returns true when running on initialization thread.
-// Only callable after initialization thread is started.
+// Returns true when called on the initialization thread.
+// May only be called after EnsureInitialized() has returned.
 bool OnInitThread();
 
 // Posts a task to run on initialization thread. Blocks until initialization
@@ -27,24 +27,29 @@ bool OnInitThread();
 void PostTaskToInitThread(const base::Location& posted_from,
                           base::OnceClosure task);
 
-// Ensure that one time initialization of Cronet global state is done. Can be
-// called from any thread. The initialization is performed on initialization
-// thread.
+// Performs one-off initialization of Cronet global state, including creating,
+// or binding to an existing thread, to run initialization and process
+// network notifications on. The implementation must be thread-safe and
+// idempotent, and must complete initialization before returning.
 void EnsureInitialized();
 
 // Creates a proxy config service appropriate for this platform that fetches the
-// system proxy settings.
+// system proxy settings. Cronet will call this API only after a prior call
+// to EnsureInitialized() has returned.
 std::unique_ptr<net::ProxyConfigService> CreateProxyConfigService(
     const scoped_refptr<base::SequencedTaskRunner>& io_task_runner);
 
 // Creates a proxy service appropriate for this platform that fetches the
-// system proxy settings.
+// system proxy settings. Cronet will call this API only after a prior call
+// to EnsureInitialized() has returned.
 std::unique_ptr<net::ProxyResolutionService> CreateProxyService(
     std::unique_ptr<net::ProxyConfigService> proxy_config_service,
     net::NetLog* net_log);
 
 // Creates default User-Agent request value, combining optional
-// |partial_user_agent| with system-dependent values.
+// |partial_user_agent| with system-dependent values. This API may be invoked
+// before EnsureInitialized(), in which case it may trigger initialization
+// itself, if necessary.
 std::string CreateDefaultUserAgent(const std::string& partial_user_agent);
 
 }  // namespace cronet

components/cronet/cronet_global_state_stubs.cc

+// Copyright 2018 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 "components/cronet/cronet_global_state.h"
+
+#include "base/at_exit.h"
+#include "base/task_scheduler/post_task.h"
+#include "base/task_scheduler/task_scheduler.h"
+#include "net/proxy_resolution/proxy_config_service.h"
+#include "net/proxy_resolution/proxy_service.h"
+#include "url/url_util.h"
+
+// This file provides minimal "stub" implementations of the Cronet global-state
+// functions for the native library build, sufficient to have cronet_tests and
+// cronet_unittests build.
+
+namespace cronet {
+
+namespace {
+
+scoped_refptr<base::SingleThreadTaskRunner> InitializeAndCreateTaskRunner() {
+  // TODO(wez): Remove this once AtExitManager dependencies are gone.
+  ignore_result(new base::AtExitManager);
+
+  url::Initialize();
+
+  // Note that in component builds this TaskScheduler will be shared with the
+  // calling process, if it also depends on //base. In particular this means
+  // that the Cronet test binaries must avoid initializing or shutting-down the
+  // TaskScheduler themselves.
+  base::TaskScheduler::CreateAndStartWithDefaultParams("cronet");
+
+  return base::CreateSingleThreadTaskRunnerWithTraits({});
+}
+
+base::SingleThreadTaskRunner* InitTaskRunner() {
+  static scoped_refptr<base::SingleThreadTaskRunner> init_task_runner =
+      InitializeAndCreateTaskRunner();
+  return init_task_runner.get();
+}
+
+}  // namespace
+
+void EnsureInitialized() {
+  ignore_result(InitTaskRunner());
+}
+
+bool OnInitThread() {
+  return InitTaskRunner()->BelongsToCurrentThread();
+}
+
+void PostTaskToInitThread(const base::Location& posted_from,
+                          base::OnceClosure task) {
+  InitTaskRunner()->PostTask(posted_from, std::move(task));
+}
+
+std::unique_ptr<net::ProxyConfigService> CreateProxyConfigService(
+    const scoped_refptr<base::SequencedTaskRunner>& io_task_runner) {
+  // TODO(https://crbug.com/813226): Add ProxyConfigService support.
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+std::unique_ptr<net::ProxyResolutionService> CreateProxyService(
+    std::unique_ptr<net::ProxyConfigService> proxy_config_service,
+    net::NetLog* net_log) {
+  // TODO(https://crbug.com/813226): Add ProxyResolutionService support.
+  NOTIMPLEMENTED();
+  return nullptr;
+}
+
+std::string CreateDefaultUserAgent(const std::string& partial_user_agent) {
+  return partial_user_agent;
+}
+
+}  // namespace cronet

components/cronet/native/BUILD.gn

@@ -31,7 +31,7 @@ source_set("cronet_native_headers") {
   ]
 }
 
-# Cronet native API implementation.
+# Cross-platform portion of Cronet native API implementation.
 source_set("cronet_native_impl") {
   deps = [
     ":cronet_native_headers",
@@ -73,6 +73,7 @@ source_set("cronet_native_unittests") {
     ":cronet_native_impl",
     "//components/cronet/native/test:cronet_native_testutil",
     "//net:test_support",
+    "//testing/gtest",
   ]
 
   configs += [ ":cronet_native_include_config" ]

components/cronet/native/runnables_unittest.cc

@@ -9,7 +9,8 @@
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/macros.h"
-#include "base/test/scoped_task_environment.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "components/cronet/native/generated/cronet.idl_impl_interface.h"
 #include "components/cronet/native/include/cronet_c.h"
 #include "components/cronet/native/test/test_util.h"
@@ -41,7 +42,8 @@ class RunnablesTest : public ::testing::Test {
 
   bool callback_called() const { return callback_called_; }
 
-  base::test::ScopedTaskEnvironment scoped_task_environment_;
+  // Provide a message loop for use by TestExecutor instances.
+  base::MessageLoop message_loop_;
 
  private:
   bool callback_called_ = false;
@@ -139,7 +141,7 @@ TEST_F(RunnablesTest, TestRunCallbackOnExecutor) {
   new_location_url = "bad";
   Cronet_UrlRequestCallback_SetClientContext(callback, this);
   Cronet_Executor_Execute(executor, runnable);
-  scoped_task_environment_.RunUntilIdle();
+  base::RunLoop().RunUntilIdle();
   ASSERT_TRUE(callback_called());
   Cronet_Executor_Destroy(executor);
 }
@@ -162,7 +164,7 @@ TEST_F(RunnablesTest, TestRunOnceClosureOnExecutor) {
                      /* request = */ nullptr, /* response_info = */ nullptr));
   Cronet_UrlRequestCallback_SetClientContext(callback, this);
   Cronet_Executor_Execute(executor, runnable);
-  scoped_task_environment_.RunUntilIdle();
+  base::RunLoop().RunUntilIdle();
   ASSERT_TRUE(callback_called());
   Cronet_Executor_Destroy(executor);
 }
@@ -190,7 +192,7 @@ TEST_F(RunnablesTest, TestCronetBuffer) {
       /* response_info = */ nullptr, buffer, /* bytes_read = */ 0));
   Cronet_UrlRequestCallback_SetClientContext(callback, this);
   Cronet_Executor_Execute(executor, runnable);
-  scoped_task_environment_.RunUntilIdle();
+  base::RunLoop().RunUntilIdle();
   ASSERT_TRUE(callback_called());
   Cronet_Executor_Destroy(executor);
 }

components/cronet/native/test/buffer_test.cc

@@ -6,7 +6,8 @@
 
 #include "base/logging.h"
 #include "base/macros.h"
-#include "base/test/scoped_task_environment.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "components/cronet/native/test/test_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -22,7 +23,8 @@ class BufferTest : public ::testing::Test {
                                        Cronet_BufferPtr buffer);
   bool on_destroy_called() const { return on_destroy_called_; }
 
-  base::test::ScopedTaskEnvironment scoped_task_environment_;
+  // Provide a message loop for use by TestExecutor instances.
+  base::MessageLoop message_loop_;
 
  private:
   void set_on_destroy_called(bool value) { on_destroy_called_ = value; }
@@ -116,7 +118,7 @@ TEST_F(BufferTest, TestCronetBufferAsync) {
       Cronet_Runnable_CreateWith(TestRunnable_DestroyBuffer);
   Cronet_Runnable_SetClientContext(runnable, buffer);
   Cronet_Executor_Execute(executor, runnable);
-  scoped_task_environment_.RunUntilIdle();
+  base::RunLoop().RunUntilIdle();
   ASSERT_TRUE(on_destroy_called());
   Cronet_Executor_Destroy(executor);
 }

components/cronet/native/test/engine_test.cc

@@ -8,7 +8,8 @@
 #include "base/files/scoped_temp_dir.h"
 #include "base/logging.h"
 #include "base/macros.h"
-#include "base/test/scoped_task_environment.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "components/cronet/native/test/test_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 

components/cronet/native/test/executors_test.cc

@@ -6,7 +6,8 @@
 
 #include "base/logging.h"
 #include "base/macros.h"
-#include "base/test/scoped_task_environment.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "components/cronet/native/test/test_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -21,7 +22,8 @@ class ExecutorsTest : public ::testing::Test {
   static void TestRunnable_Run(Cronet_RunnablePtr self);
   bool runnable_called() const { return runnable_called_; }
 
-  base::test::ScopedTaskEnvironment scoped_task_environment_;
+  // Provide a message loop for use by TestExecutor instances.
+  base::MessageLoop message_loop_;
 
  private:
   void set_runnable_called(bool value) { runnable_called_ = value; }
@@ -57,7 +59,7 @@ TEST_F(ExecutorsTest, TestCustom) {
       Cronet_Executor_CreateWith(TestExecutor_Execute);
   Cronet_Executor_Execute(executor, runnable);
   Cronet_Executor_Destroy(executor);
-  scoped_task_environment_.RunUntilIdle();
+  base::RunLoop().RunUntilIdle();
   ASSERT_TRUE(runnable_called());
 }
 
@@ -69,7 +71,7 @@ TEST_F(ExecutorsTest, TestTestExecutor) {
   Cronet_ExecutorPtr executor = cronet::test::CreateTestExecutor();
   Cronet_Executor_Execute(executor, runnable);
   Cronet_Executor_Destroy(executor);
-  scoped_task_environment_.RunUntilIdle();
+  base::RunLoop().RunUntilIdle();
   ASSERT_TRUE(runnable_called());
 }
 

components/cronet/native/test/test_util.cc

@@ -9,7 +9,7 @@
 
 #include "base/bind.h"
 #include "base/strings/stringprintf.h"
-#include "base/task_scheduler/post_task.h"
+#include "base/threading/sequenced_task_runner_handle.h"
 #include "components/cronet/native/generated/cronet.idl_c.h"
 #include "net/base/net_errors.h"
 #include "net/cert/mock_cert_verifier.h"
@@ -20,7 +20,8 @@ void TestExecutor_Execute(Cronet_ExecutorPtr self,
                           Cronet_RunnablePtr runnable) {
   CHECK(self);
   DVLOG(1) << "Post Task";
-  base::PostTask(FROM_HERE, base::BindOnce(Cronet_Runnable_Run, runnable));
+  base::SequencedTaskRunnerHandle::Get()->PostTask(
+      FROM_HERE, base::BindOnce(Cronet_Runnable_Run, runnable));
 }
 }  // namespace
 

components/cronet/native/test/url_request_test.cc

@@ -8,8 +8,9 @@
 #include "base/files/scoped_temp_dir.h"
 #include "base/logging.h"
 #include "base/macros.h"
+#include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/synchronization/waitable_event.h"
-#include "base/test/scoped_task_environment.h"
 #include "components/cronet/native/test/test_url_request_callback.h"
 #include "components/cronet/native/test/test_util.h"
 #include "components/cronet/test/test_server.h"
@@ -104,7 +105,8 @@ class UrlRequestTest : public ::testing::Test {
   }
 
  protected:
-  base::test::ScopedTaskEnvironment scoped_task_environment_;
+  // Provide a message loop for use by TestExecutor instances.
+  base::MessageLoop message_loop_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(UrlRequestTest);

net/dns/dns_util.h

@@ -71,6 +71,7 @@ enum AddressListDeltaType {
 
 // Compares two AddressLists to see how similar or different their addresses
 // are. (See |AddressListDeltaType| for details of exactly what's checked.)
+NET_EXPORT
 AddressListDeltaType FindAddressListDeltaType(const AddressList& a,
                                               const AddressList& b);