Add WebTaskRunner::postCancellableTask

third_party/WebKit/Source/platform/scheduler/test/fake_web_task_runner.h

Index: third_party/WebKit/Source/platform/scheduler/test/fake_web_task_runner.h
diff --git a/third_party/WebKit/Source/platform/scheduler/test/fake_web_task_runner.h b/third_party/WebKit/Source/platform/scheduler/test/fake_web_task_runner.h
index 9bdfea96ae78fca127d1f8897c1871ee01bdff7f..4454f80007125501b81b7cf3bd5d330c1e5400a0 100644
--- a/third_party/WebKit/Source/platform/scheduler/test/fake_web_task_runner.h
+++ b/third_party/WebKit/Source/platform/scheduler/test/fake_web_task_runner.h
@@ -9,6 +9,7 @@
 #include "public/platform/WebTaskRunner.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefPtr.h"
+#include "base/memory/ref_counted.h"
 
 namespace blink {
 namespace scheduler {
@@ -33,11 +34,16 @@ class FakeWebTaskRunner : public WebTaskRunner {
   double monotonicallyIncreasingVirtualTimeSeconds() const override;
   SingleThreadTaskRunner* toSingleThreadTaskRunner() override;
 
+  void runUntilIdle();
+
  private:
   class Data;
+  class BaseTaskRunner;
   RefPtr<Data> data_;
+  scoped_refptr<BaseTaskRunner> base_task_runner_;
 
-  FakeWebTaskRunner(PassRefPtr<Data> data);
+  FakeWebTaskRunner(PassRefPtr<Data> data,
+                    scoped_refptr<BaseTaskRunner> base_task_runner);
 
   DISALLOW_COPY_AND_ASSIGN(FakeWebTaskRunner);
 };