[Code health] Move TickAnimationsIf to anonymous namespace

The TickAnimationsIf is not a member function and is used in the same
file. In this case, it should be in the anonymous namespace.

This CL doesn't introduce any behavior change.

Bug: None
Change-Id: I4cc3340335dfbd8b9c3b50765710d8c46bbda603
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1604110
Reviewed-by: Yi Gu <yigu@chromium.org>
Reviewed-by: Majid Valipour <majidvp@chromium.org>
Reviewed-by: Stephen McGruer <smcgruer@chromium.org>
Commit-Queue: Xida Chen <xidachen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#659119}

cc/animation/animation_host.cc

@@ -47,6 +47,19 @@ AnimationWorkletMutationState ToAnimationWorkletMutationState(
   }
 }
 
+bool TickAnimationsIf(AnimationHost::AnimationsList animations,
+                      base::TimeTicks monotonic_time,
+                      bool (*predicate)(const Animation&)) {
+  bool did_tick = false;
+  for (auto& it : animations) {
+    if (predicate(*it)) {
+      it->Tick(monotonic_time);
+      did_tick = true;
+    }
+  }
+  return did_tick;
+}
+
 }  // namespace
 
 std::unique_ptr<AnimationHost> AnimationHost::CreateMainInstance() {
@@ -356,19 +369,6 @@ bool AnimationHost::ActivateAnimations() {
   return true;
 }
 
-bool TickAnimationsIf(AnimationHost::AnimationsList animations,
-                      base::TimeTicks monotonic_time,
-                      bool (*predicate)(const Animation&)) {
-  bool did_tick = false;
-  for (auto& it : animations) {
-    if (predicate(*it)) {
-      it->Tick(monotonic_time);
-      did_tick = true;
-    }
-  }
-  return did_tick;
-}
-
 bool AnimationHost::TickAnimations(base::TimeTicks monotonic_time,
                                    const ScrollTree& scroll_tree,
                                    bool is_active_tree) {