3 files changed, 12 insertions, 6 deletions
diff --git a/base/test/simple_test_clock.cc b/base/test/simple_test_clock.cc
index 3bd6080..a2bdc2a 100644
--- a/base/test/simple_test_clock.cc
+++ b/base/test/simple_test_clock.cc
@@ -20,4 +20,9 @@ void SimpleTestClock::Advance(TimeDelta delta) {
   now_ += delta;
 }
 
+void SimpleTestClock::SetNow(Time now) {
+  AutoLock lock(lock_);
+  now_ = now;
+}
+
 }  // namespace base
diff --git a/base/test/simple_test_clock.h b/base/test/simple_test_clock.h
index a83312f..f96dabf 100644
--- a/base/test/simple_test_clock.h
+++ b/base/test/simple_test_clock.h
@@ -13,7 +13,7 @@
 namespace base {
 
 // SimpleTestClock is a Clock implementation that gives control over
-// the returned Time objects.  All methods can be called from any
+// the returned Time objects.  All methods may be called from any
 // thread.
 class SimpleTestClock : public Clock {
  public:
@@ -23,10 +23,12 @@ class SimpleTestClock : public Clock {
 
   virtual Time Now() OVERRIDE;
 
-  // Sets the current time forward by |delta|.  Safe to call from any
-  // thread.
+  // Advances the clock by |delta|.
   void Advance(TimeDelta delta);
 
+  // Sets the clock to the given time.
+  void SetNow(Time now);
+
  private:
   // Protects |now_|.
   Lock lock_;
diff --git a/base/test/simple_test_tick_clock.h b/base/test/simple_test_tick_clock.h
index c53301b..2809774 100644
--- a/base/test/simple_test_tick_clock.h
+++ b/base/test/simple_test_tick_clock.h
@@ -13,7 +13,7 @@
 namespace base {
 
 // SimpleTestTickClock is a TickClock implementation that gives
-// control over the returned TimeTicks objects.  All methods can be
+// control over the returned TimeTicks objects.  All methods may be
 // called from any thread.
 class SimpleTestTickClock : public TickClock {
  public:
@@ -23,8 +23,7 @@ class SimpleTestTickClock : public TickClock {
 
   virtual TimeTicks NowTicks() OVERRIDE;
 
-  // Sets the current time forward by |delta|.  Safe to call from any
-  // thread.
+  // Advances the clock by |delta|, which must not be negative.
   void Advance(TimeDelta delta);
 
  private: