Fix black background when locking with fullscreen window:

ui/compositor/layer_animator.cc

Index: ui/compositor/layer_animator.cc
diff --git a/ui/compositor/layer_animator.cc b/ui/compositor/layer_animator.cc
index 98261fe539e1e287eb62f6cedcd082f70cc12c8a..71cb0ca7b7acb8d2d5c165a94e76a03d772075a7 100644
--- a/ui/compositor/layer_animator.cc
+++ b/ui/compositor/layer_animator.cc
@@ -86,6 +86,14 @@ LayerAnimator* LayerAnimator::CreateImplicitAnimator() {
       base::TimeDelta::FromMilliseconds(kDefaultTransitionDurationMs));
 }
 
+// static
+scoped_ptr<test::AnimationContainerTestHelper>
+LayerAnimator::CreateAnimatorHelperForTest() {
+  scoped_ptr<test::AnimationContainerTestHelper> result;
+  result.reset(new test::AnimationContainerTestHelper(GetAnimationContainer()));
+  return result.Pass();
+}
+
 // This macro provides the implementation for the setter and getter (well,
 // the getter of the target value) for an animated property. For example,
 // it is used for the implementations of SetTransform and GetTargetTransform.
@@ -183,7 +191,7 @@ void LayerAnimator::StartTogether(
     if (GetAnimationContainer()->is_running())
       last_step_time_ = GetAnimationContainer()->last_tick_time();
     else
-      last_step_time_ = base::TimeTicks::Now();
+      last_step_time_ = GetAnimationContainer()->GetCurrentTime();
   }
 
   // Collect all the affected properties.
@@ -678,7 +686,7 @@ bool LayerAnimator::StartSequenceImmediately(LayerAnimationSequence* sequence) {
   else if (GetAnimationContainer()->is_running())
     start_time = GetAnimationContainer()->last_tick_time();
   else
-    start_time = base::TimeTicks::Now();
+    start_time = GetAnimationContainer()->GetCurrentTime();
 
   running_animations_.push_back(
       RunningAnimation(sequence->AsWeakPtr(), start_time));