Optimize posting of WTF::Closure and improve scheduler test mocks

third_party/WebKit/Source/platform/scheduler/child/web_task_runner_impl.h

Index: third_party/WebKit/Source/platform/scheduler/child/web_task_runner_impl.h
diff --git a/third_party/WebKit/Source/platform/scheduler/child/web_task_runner_impl.h b/third_party/WebKit/Source/platform/scheduler/child/web_task_runner_impl.h
index ac3cfabebf7bcced4b512c0be55f6fe351686a3f..b95f5f4683f40cad7f722524b577960575161bfc 100644
--- a/third_party/WebKit/Source/platform/scheduler/child/web_task_runner_impl.h
+++ b/third_party/WebKit/Source/platform/scheduler/child/web_task_runner_impl.h
@@ -29,11 +29,16 @@ class BLINK_PLATFORM_EXPORT WebTaskRunnerImpl : public WebTaskRunner {
   void postDelayedTask(const WebTraceLocation& web_location,
                        WebTaskRunner::Task* task,
                        double delayMs) override;
+  TaskQueue::TaskHandle postCancellableDelayedTask(
+      const tracked_objects::Location& from_here,
+      const base::Closure& task,
+      double delayMs) override;
+  bool cancelTask(const TaskQueue::TaskHandle& handle) override;
   bool runsTasksOnCurrentThread() override;
   double virtualTimeSeconds() const override;
   double monotonicallyIncreasingVirtualTimeSeconds() const override;
   std::unique_ptr<WebTaskRunner> clone() override;
-  base::SingleThreadTaskRunner* taskRunner() override;
+  base::SingleThreadTaskRunner* toSingleThreadTaskRunner() override;
 
   // WebTaskRunner::Task should be wrapped by base::Passed() when
   // used with base::Bind(). See https://crbug.com/551356.