CC::Animations should use TimeTicks & TimeDelta to represent time

cc/trees/layer_tree_host_unittest_animation.cc

 // Copyright 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 "cc/trees/layer_tree_host.h"
 
 #include "cc/animation/animation_curve.h"
 #include "cc/animation/layer_animation_controller.h"
 #include "cc/animation/scroll_offset_animation_curve.h"
 #include "cc/animation/timing_function.h"
@@ skipping 550 matching lines @@
   }
 
   virtual void NotifyAnimationStarted(
       base::TimeTicks monotonic_time,
       Animation::TargetProperty target_property) OVERRIDE {
     LayerAnimationController* controller =
         layer_tree_host()->root_layer()->children()[0]->
         layer_animation_controller();
     Animation* animation =
         controller->GetAnimation(Animation::Opacity);
-    main_start_time_ = animation->start_time();
+    main_start_time_ =
+        (animation->start_time() - base::TimeTicks()).InSecondsF();
     controller->RemoveAnimation(animation->id());
 
     if (impl_start_time_ > 0.0)
       EndTest();
   }
 
   virtual void UpdateAnimationState(
       LayerTreeHostImpl* impl_host,
       bool has_unfinished_animation) OVERRIDE {
     LayerAnimationController* controller =
         impl_host->active_tree()->root_layer()->children()[0]->
         layer_animation_controller();
     Animation* animation =
         controller->GetAnimation(Animation::Opacity);
     if (!animation)
       return;
 
-    impl_start_time_ = animation->start_time();
+    impl_start_time_ =
+        (animation->start_time() - base::TimeTicks()).InSecondsF();
     controller->RemoveAnimation(animation->id());
 
     if (main_start_time_ > 0.0)
       EndTest();
   }
 
   virtual void AfterTest() OVERRIDE {
     EXPECT_FLOAT_EQ(impl_start_time_, main_start_time_);
   }
 
@@ skipping 639 matching lines @@
   int num_draw_attempts_;
   base::TimeTicks last_main_thread_tick_time_;
   base::TimeTicks expected_impl_tick_time_;
 };
 
 // Only the non-impl-paint multi-threaded compositor freezes animations.
 MULTI_THREAD_NOIMPL_TEST_F(LayerTreeHostAnimationTestFrozenAnimationTickTime);
 
 }  // namespace
 }  // namespace cc