Fix some IWYU errors in advance of removing some #includes.

Bug: 242216
Change-Id: Ia2b406e86e4989be41f9213e16f6c0bc04990aa1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3009974
Commit-Queue: Peter Kasting <pkasting@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Auto-Submit: Peter Kasting <pkasting@chromium.org>
Reviewed-by: danakj <danakj@chromium.org>
Owners-Override: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#898962}

diff --git a/cc/animation/animation_timeline.cc b/cc/animation/animation_timeline.cc
index d7067c5..ac3a92e 100644
--- a/cc/animation/animation_timeline.cc
+++ b/cc/animation/animation_timeline.cc

@@ -5,7 +5,10 @@
 #include "cc/animation/animation_timeline.h"
 
 #include <algorithm>
+#include <utility>
+#include <vector>
 
+#include "base/time/time.h"
 #include "cc/animation/animation.h"
 #include "cc/animation/animation_host.h"
 #include "cc/trees/property_tree.h"