chore: cherry-pick cc20b36a5845 from chromium (#29997)

* chore: cherry-pick cc20b36a5845 from chromium

* chore: update patches

Co-authored-by: PatchUp <73610968+patchup[bot]@users.noreply.github.com>

patches/chromium/.patches

@@ -114,3 +114,4 @@ cherry-pick-3299d70b7d0f.patch
 support_runtime_configurable_key_storage_on_linux_os_crypto.patch
 make_keychain_service_account_optionally_configurable_at_runtime.patch
 don_t_run_pcscan_notifythreadcreated_if_pcscan_is_disabled.patch
+cherry-pick-cc20b36a5845.patch

patches/chromium/cherry-pick-cc20b36a5845.patch

@@ -0,0 +1,41 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Philip Rogers <pdr@chromium.org>
+Date: Wed, 19 May 2021 16:11:29 +0000
+Subject: Use a 100ms timer in
+ MacScrollbarAnimatorImpl::StartScrollbarPaintTimer
+
+MacScrollbarAnimatorImpl::StartScrollbarPaintTimer has a timer that
+runs while ShouldSuspendScrollAnimations is true. The timer was changed
+from 100ms to 1ms in https://crrev.com/376453. This was later changed to
+0ms in https://crrev.com/434428 which caused a performance regression
+(https://crbug.com/713669). The timer was then changed back to 1ms in
+https://crrev.com/470823 with a comment about giving other tasks time to
+cancel the timer. This patch restores the 100ms timer. The comment has
+been removed because this timer is more of a polling mechanism.
+
+Bug: 1090000
+Change-Id: I4041d9ba5869abbe4ff7d55d56d921c7d90a72ad
+Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2903830
+Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
+Commit-Queue: Philip Rogers <pdr@chromium.org>
+Cr-Commit-Position: refs/heads/master@{#884506}
+
+diff --git a/third_party/blink/renderer/core/scroll/mac_scrollbar_animator_impl.mm b/third_party/blink/renderer/core/scroll/mac_scrollbar_animator_impl.mm
+index cb3c5b0493410a1cb8d099ec3349e8cbb8dd629d..b7257f954d4f7f85128b5fd24651c27d2ce8bd85 100644
+--- a/third_party/blink/renderer/core/scroll/mac_scrollbar_animator_impl.mm
++++ b/third_party/blink/renderer/core/scroll/mac_scrollbar_animator_impl.mm
+@@ -814,13 +814,11 @@ - (void)invalidate {
+ }
+
+ void MacScrollbarAnimatorImpl::StartScrollbarPaintTimer() {
+-  // Post a task with 1 ms delay to give a chance to run other immediate tasks
+-  // that may cancel this.
+   initial_scrollbar_paint_task_handle_ = PostDelayedCancellableTask(
+       *task_runner_, FROM_HERE,
+       WTF::Bind(&MacScrollbarAnimatorImpl::InitialScrollbarPaintTask,
+                 WrapWeakPersistent(this)),
+-      base::TimeDelta::FromMilliseconds(1));
++      base::TimeDelta::FromMilliseconds(100));
+ }
+
+ bool MacScrollbarAnimatorImpl::ScrollbarPaintTimerIsActive() const {