Switch media/blink unittests to use a mock time source.

Also provides BlinkPlatformWithTaskEnvironment::GetTaskEnvironment()
so that unittests can get access to it.  Previously, it was hidden
in //media/blink/run_all_unittests.cc .

Change-Id: Ib2a13045fd377d603f8b08cba9e78da76dc67099
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1868838Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Frank Liberato <liberato@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707511}

media/blink/BUILD.gn

@@ -131,6 +131,8 @@ test("media_blink_unittests") {
   ]
 
   sources = [
+    "blink_platform_with_task_environment.cc",
+    "blink_platform_with_task_environment.h",
     "buffered_data_source_host_impl_unittest.cc",
     "cache_util_unittest.cc",
     "interval_map_unittest.cc",

media/blink/blink_platform_with_task_environment.cc

+// Copyright 2019 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 "media/blink/blink_platform_with_task_environment.h"
+
+namespace media {
+
+BlinkPlatformWithTaskEnvironment::BlinkPlatformWithTaskEnvironment()
+    : task_environment_(base::test::TaskEnvironment::TimeSource::MOCK_TIME),
+      main_thread_scheduler_(
+          blink::scheduler::WebThreadScheduler::CreateMainThreadScheduler()) {}
+
+BlinkPlatformWithTaskEnvironment::~BlinkPlatformWithTaskEnvironment() {
+  main_thread_scheduler_->Shutdown();
+}
+
+blink::scheduler::WebThreadScheduler*
+BlinkPlatformWithTaskEnvironment::GetMainThreadScheduler() {
+  return main_thread_scheduler_.get();
+}
+
+// static
+base::test::TaskEnvironment*
+BlinkPlatformWithTaskEnvironment::GetTaskEnvironment() {
+  return &static_cast<BlinkPlatformWithTaskEnvironment*>(
+              blink::Platform::Current())
+              ->task_environment_;
+}
+
+}  // namespace media

media/blink/blink_platform_with_task_environment.h

+// Copyright 2019 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.
+
+#ifndef MEDIA_BLINK_BLINK_PLATFORM_WITH_TASK_ENVIRONMENT_H_
+#define MEDIA_BLINK_BLINK_PLATFORM_WITH_TASK_ENVIRONMENT_H_
+
+#include "base/macros.h"
+#include "base/test/task_environment.h"
+#include "third_party/blink/public/platform/scheduler/web_thread_scheduler.h"
+#include "third_party/blink/public/web/blink.h"
+
+namespace media {
+
+// We must use a custom blink::Platform that ensures the main thread scheduler
+// knows about the TaskEnvironment.
+class BlinkPlatformWithTaskEnvironment : public blink::Platform {
+ public:
+  BlinkPlatformWithTaskEnvironment();
+  ~BlinkPlatformWithTaskEnvironment() override;
+
+  blink::scheduler::WebThreadScheduler* GetMainThreadScheduler();
+
+  // Returns |task_environment_| from the current blink::Platform.
+  static base::test::TaskEnvironment* GetTaskEnvironment();
+
+ private:
+  base::test::TaskEnvironment task_environment_;
+  std::unique_ptr<blink::scheduler::WebThreadScheduler> main_thread_scheduler_;
+
+  DISALLOW_COPY_AND_ASSIGN(BlinkPlatformWithTaskEnvironment);
+};
+
+}  // namespace media
+
+#endif  // MEDIA_BLINK_BLINK_PLATFORM_WITH_TASK_ENVIRONMENT_H_

media/blink/run_all_unittests.cc

@@ -5,13 +5,12 @@
 #include "base/bind.h"
 #include "base/macros.h"
 #include "base/test/launcher/unit_test_launcher.h"
-#include "base/test/task_environment.h"
 #include "base/test/test_suite.h"
 #include "build/build_config.h"
 #include "media/base/media.h"
+#include "media/blink/blink_platform_with_task_environment.h"
 #include "services/service_manager/public/cpp/binder_registry.h"
 #include "third_party/blink/public/platform/scheduler/test/renderer_scheduler_test_support.h"
-#include "third_party/blink/public/platform/scheduler/web_thread_scheduler.h"
 #include "third_party/blink/public/web/blink.h"
 
 #if defined(OS_ANDROID)
@@ -25,6 +24,8 @@
 #if defined(V8_USE_EXTERNAL_STARTUP_DATA)
 #include "gin/v8_initializer.h"
 
+using media::BlinkPlatformWithTaskEnvironment;
+
 constexpr gin::V8Initializer::V8SnapshotFileType kSnapshotType =
 #if defined(USE_V8_CONTEXT_SNAPSHOT)
     gin::V8Initializer::V8SnapshotFileType::kWithAdditionalContext;
@@ -33,30 +34,6 @@ constexpr gin::V8Initializer::V8SnapshotFileType kSnapshotType =
 #endif  // defined(USE_V8_CONTEXT_SNAPSHOT)
 #endif  // defined(V8_USE_EXTERNAL_STARTUP_DATA)
 
-// We must use a custom blink::Platform that ensures the main thread scheduler
-// knows about the TaskEnvironment.
-class BlinkPlatformWithTaskEnvironment : public blink::Platform {
- public:
-  BlinkPlatformWithTaskEnvironment()
-      : main_thread_scheduler_(
-            blink::scheduler::WebThreadScheduler::CreateMainThreadScheduler()) {
-  }
-
-  ~BlinkPlatformWithTaskEnvironment() override {
-    main_thread_scheduler_->Shutdown();
-  }
-
-  blink::scheduler::WebThreadScheduler* GetMainThreadScheduler() {
-    return main_thread_scheduler_.get();
-  }
-
- private:
-  base::test::TaskEnvironment task_environment_;
-  std::unique_ptr<blink::scheduler::WebThreadScheduler> main_thread_scheduler_;
-
-  DISALLOW_COPY_AND_ASSIGN(BlinkPlatformWithTaskEnvironment);
-};
-
 class MediaBlinkTestSuite : public base::TestSuite {
  public:
   MediaBlinkTestSuite(int argc, char** argv) : base::TestSuite(argc, argv) {}