Update from https://crrev.com/315085

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 1078 matching lines @@
 
     // Block activation until the running animation has a chance to produce a
     // scroll delta.
     gfx::Vector2dF scroll_delta = scroll_layer_impl->ScrollDelta();
     if (scroll_delta.x() < 1.f || scroll_delta.y() < 1.f)
       return;
 
     host_impl->BlockNotifyReadyToActivateForTesting(false);
   }
 
+  void WillActivateTreeOnThread(LayerTreeHostImpl* host_impl) override {
+    if (!host_impl->settings().impl_side_painting)
+      return;
+    if (host_impl->pending_tree()->source_frame_number() != 1)
+      return;
+    LayerImpl* scroll_layer_impl =
+        host_impl->pending_tree()->root_layer()->children()[0];
+    EXPECT_EQ(final_postion_, scroll_layer_impl->CurrentScrollOffset());
+  }
+
   void DidActivateTreeOnThread(LayerTreeHostImpl* host_impl) override {
+    if (host_impl->active_tree()->source_frame_number() != 1)
+      return;
     LayerImpl* scroll_layer_impl =
         host_impl->active_tree()->root_layer()->children()[0];
-    if (scroll_layer_impl->layer_animation_controller()->GetAnimation(
-            Animation::ScrollOffset))
-      return;
-
     EXPECT_EQ(final_postion_, scroll_layer_impl->CurrentScrollOffset());
     EndTest();
   }
 
   void AfterTest() override {
     EXPECT_EQ(final_postion_, scroll_layer_->scroll_offset());
   }
 
  private:
   FakeContentLayerClient client_;
@@ skipping 148 matching lines @@
  private:
   scoped_refptr<Layer> content_;
   int num_swap_buffers_;
 };
 
 SINGLE_AND_MULTI_THREAD_TEST_F(
     LayerTreeHostAnimationTestAddAnimationAfterAnimating);
 
 }  // namespace
 }  // namespace cc