ui: Cleanup class/struct forward declarations

cc/trees/layer_tree_host_unittest_animation.cc

Index: cc/trees/layer_tree_host_unittest_animation.cc
diff --git a/cc/trees/layer_tree_host_unittest_animation.cc b/cc/trees/layer_tree_host_unittest_animation.cc
index c2d83cd4c9738a262b9ff999d4f38774e9b9a02f..b6c4053e7b9b86057c6ac41cfa01d442dca3faee 100644
--- a/cc/trees/layer_tree_host_unittest_animation.cc
+++ b/cc/trees/layer_tree_host_unittest_animation.cc
@@ -44,7 +44,7 @@ class LayerTreeHostAnimationTest : public LayerTreeTest {
   }
 
   void AttachPlayersToTimeline() {
-    layer_tree()->animation_host()->AddAnimationTimeline(timeline_.get());
+    animation_host()->AddAnimationTimeline(timeline_.get());
     layer_tree()->SetElementIdsForTesting();
     timeline_->AttachPlayer(player_.get());
     timeline_->AttachPlayer(player_child_.get());
@@ -800,14 +800,10 @@ class LayerTreeHostAnimationTestScrollOffsetAnimationTakeover
     if (layer_tree_host()->SourceFrameNumber() == 1) {
       // Add an update after the first commit to trigger the animation takeover
       // path.
-      layer_tree()
-          ->animation_host()
-          ->scroll_offset_animations()
-          .AddTakeoverUpdate(scroll_layer_->element_id());
-      EXPECT_TRUE(layer_tree()
-                      ->animation_host()
-                      ->scroll_offset_animations()
-                      .HasUpdatesForTesting());
+      animation_host()->scroll_offset_animations().AddTakeoverUpdate(
+          scroll_layer_->element_id());
+      EXPECT_TRUE(
+          animation_host()->scroll_offset_animations().HasUpdatesForTesting());
     }
   }
 
@@ -874,21 +870,14 @@ class LayerTreeHostAnimationTestScrollOffsetAnimationAdjusted
     if (layer_tree_host()->SourceFrameNumber() == 1) {
       // Add an update after the first commit to trigger the animation update
       // path.
-      layer_tree()
-          ->animation_host()
-          ->scroll_offset_animations()
-          .AddAdjustmentUpdate(scroll_layer_->element_id(),
-                               gfx::Vector2dF(100.f, 100.f));
-      EXPECT_TRUE(layer_tree()
-                      ->animation_host()
-                      ->scroll_offset_animations()
-                      .HasUpdatesForTesting());
+      animation_host()->scroll_offset_animations().AddAdjustmentUpdate(
+          scroll_layer_->element_id(), gfx::Vector2dF(100.f, 100.f));
+      EXPECT_TRUE(
+          animation_host()->scroll_offset_animations().HasUpdatesForTesting());
     } else if (layer_tree_host()->SourceFrameNumber() == 2) {
       // Verify that the update queue is cleared after the update is applied.
-      EXPECT_FALSE(layer_tree()
-                       ->animation_host()
-                       ->scroll_offset_animations()
-                       .HasUpdatesForTesting());
+      EXPECT_FALSE(
+          animation_host()->scroll_offset_animations().HasUpdatesForTesting());
     }
   }
 
@@ -1254,7 +1243,7 @@ class LayerTreeHostAnimationTestAnimatedLayerRemovedAndAdded
 
     layer_tree()->SetElementIdsForTesting();
 
-    layer_tree()->animation_host()->AddAnimationTimeline(timeline_.get());
+    animation_host()->AddAnimationTimeline(timeline_.get());
     timeline_->AttachPlayer(player_.get());
     player_->AttachElement(layer_->element_id());
     DCHECK(player_->element_animations());
@@ -1271,7 +1260,7 @@ class LayerTreeHostAnimationTestAnimatedLayerRemovedAndAdded
             player_->element_animations()->has_element_in_active_list());
         EXPECT_FALSE(
             player_->element_animations()->has_element_in_pending_list());
-        EXPECT_TRUE(layer_tree()->animation_host()->NeedsAnimateLayers());
+        EXPECT_TRUE(animation_host()->NeedsAnimateLayers());
         break;
       case 1:
         layer_->RemoveFromParent();
@@ -1279,7 +1268,7 @@ class LayerTreeHostAnimationTestAnimatedLayerRemovedAndAdded
             player_->element_animations()->has_element_in_active_list());
         EXPECT_FALSE(
             player_->element_animations()->has_element_in_pending_list());
-        EXPECT_FALSE(layer_tree()->animation_host()->NeedsAnimateLayers());
+        EXPECT_FALSE(animation_host()->NeedsAnimateLayers());
         break;
       case 2:
         layer_tree()->root_layer()->AddChild(layer_);
@@ -1287,7 +1276,7 @@ class LayerTreeHostAnimationTestAnimatedLayerRemovedAndAdded
             player_->element_animations()->has_element_in_active_list());
         EXPECT_FALSE(
             player_->element_animations()->has_element_in_pending_list());
-        EXPECT_TRUE(layer_tree()->animation_host()->NeedsAnimateLayers());
+        EXPECT_TRUE(animation_host()->NeedsAnimateLayers());
         break;
     }
   }