Revert "Handle direction control in compositor Animations"

cc/animation/animation.cc

Index: cc/animation/animation.cc
diff --git a/cc/animation/animation.cc b/cc/animation/animation.cc
index a84b181edc37d917022a14a5c01bd83193365abf..263c34743dcf8d19ee4a9b958beb88e6323abb08 100644
--- a/cc/animation/animation.cc
+++ b/cc/animation/animation.cc
@@ -65,7 +65,7 @@ Animation::Animation(scoped_ptr<AnimationCurve> curve,
       run_state_(WaitingForTargetAvailability),
       iterations_(1),
       start_time_(0),
-      direction_(Normal),
+      alternates_direction_(false),
       time_offset_(0),
       needs_synchronized_start_time_(false),
       received_finished_event_(false),
@@ -173,8 +173,8 @@ double Animation::TrimTimeToCurrentIteration(double monotonic_time) const {
       needs_synchronized_start_time())
     trimmed = time_offset_;
 
-  // Return 0 if we are before the start of the animation
-  if (trimmed < 0)
+  // Zero is always the start of the animation.
+  if (trimmed <= 0)
     return 0;
 
   // Always return zero if we have no iterations.
@@ -185,32 +185,26 @@ double Animation::TrimTimeToCurrentIteration(double monotonic_time) const {
   if (curve_->Duration() <= 0)
     return 0;
 
-  // check if we are past active interval
-  bool is_past_total_duration =
-      (iterations_ > 0 && trimmed >= curve_->Duration() * iterations_);
+  // If less than an iteration duration, just return trimmed.
+  if (trimmed < curve_->Duration())
+    return trimmed;
 
-  // We need to know the current iteration if we're alternating.
-  int iteration = 0;
-
-  // If we are past the active interval, return iteration duration.
-  if (is_past_total_duration) {
-    iteration = iterations_;
-    trimmed = curve_->Duration();
-  } else {
-    iteration = static_cast<int>(trimmed / curve_->Duration());
-    // Calculate x where trimmed = x + n * curve_->Duration() for some positive
-    // integer n.
-    trimmed = fmod(trimmed, curve_->Duration());
+  // If greater than or equal to the total duration, return iteration duration.
+  if (iterations_ >= 0 && trimmed >= curve_->Duration() * iterations_) {
+    if (alternates_direction_ && !(iterations_ % 2))
+      return 0;
+    return curve_->Duration();
   }
 
-  // check if we are running the animation in reverse direction for the current
-  // iteration
-  bool reverse = (direction_ == Reverse) ||
-                 (direction_ == Alternate && iteration % 2 == 1) ||
-                 (direction_ == AlternateReverse && iteration % 2 == 0);
+  // We need to know the current iteration if we're alternating.
+  int iteration = static_cast<int>(trimmed / curve_->Duration());
+
+  // Calculate x where trimmed = x + n * curve_->Duration() for some positive
+  // integer n.
+  trimmed = fmod(trimmed, curve_->Duration());
 
-  // if we are running the animation in reverse direction, reverse the result
-  if (reverse)
+  // If we're alternating and on an odd iteration, reverse the direction.
+  if (alternates_direction_ && iteration % 2 == 1)
     return curve_->Duration() - trimmed;
 
   return trimmed;
@@ -230,7 +224,7 @@ scoped_ptr<Animation> Animation::CloneAndInitialize(RunState initial_run_state,
   to_return->pause_time_ = pause_time_;
   to_return->total_paused_time_ = total_paused_time_;
   to_return->time_offset_ = time_offset_;
-  to_return->direction_ = direction_;
+  to_return->alternates_direction_ = alternates_direction_;
   DCHECK(!to_return->is_controlling_instance_);
   to_return->is_controlling_instance_ = true;
   return to_return.Pass();