Refactor: Shelf Widget

ui/compositor/layer_animation_element.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/compositor/layer_animation_element.h"
 
 #include "base/compiler_specific.h"
 #include "cc/animation.h"
 #include "cc/animation_id_provider.h"
 #include "ui/base/animation/tween.h"
@@ skipping 537 matching lines @@
 
   if (effective_start_time_ == base::TimeTicks()) {
     // This hasn't actually started yet.
     need_draw = false;
     last_progressed_fraction_ = 0.0;
     return need_draw;
   }
 
   base::TimeDelta elapsed = now - effective_start_time_;
   if ((duration_ > base::TimeDelta()) && (elapsed < duration_))
-    t = elapsed.InMillisecondsF() / duration_.InMillisecondsF();
+    t = std::max(0.0, elapsed.InMillisecondsF() / duration_.InMillisecondsF());
   need_draw = OnProgress(Tween::CalculateValue(tween_type_, t), delegate);
   first_frame_ = t == 1.0;
   last_progressed_fraction_ = t;
   return need_draw;
 }
 
 bool LayerAnimationElement::IsFinished(base::TimeTicks time,
                                        base::TimeDelta* total_duration) {
   // If an effective start has been requested but the effective start time
   // hasn't yet been set, the animation is not finished, regardless of the
@@ skipping 126 matching lines @@
 }
 
 // static
 LayerAnimationElement* LayerAnimationElement::CreateColorElement(
     SkColor color,
     base::TimeDelta duration) {
   return new ColorTransition(color, duration);
 }
 
 }  // namespace ui