Implement a poor man's PostAfterStartupTask() function.

base/synchronization/cancellation_flag.h

Index: base/synchronization/cancellation_flag.h
diff --git a/base/synchronization/cancellation_flag.h b/base/synchronization/cancellation_flag.h
index 51a4def1eb31984f0eafeb97dbd0d8678541ee59..555f2da0794cc512dc548fd4b6f4b5c7835a382e 100644
--- a/base/synchronization/cancellation_flag.h
+++ b/base/synchronization/cancellation_flag.h
@@ -29,6 +29,9 @@ class BASE_EXPORT CancellationFlag {
   void Set();
   bool IsSet() const;  // Returns true iff the flag was set.
 
+  // Intended to help with testing.
+  void UnsafeReset();

[jam, 2015/04/08 20:34:27]

nit: testing methods need to end with ForTesting() so that presubmit checks
catch if they're called by non-testing code

[michaeln, 2015/04/08 21:57:25]

Done.

+
  private:
   base::subtle::Atomic32 flag_;
 #if !defined(NDEBUG)