Cut scroll threshold in half for pagination

Bug: 760279
Change-Id: I122f307af8047932ee593e8f4baccd5591d74ad4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2622767
Reviewed-by: Ahmed Mehfooz <amehfooz@chromium.org>
Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Commit-Queue: Angus McLean <angusmclean@chromium.org>
Cr-Commit-Position: refs/heads/master@{#844155}

ash/public/cpp/pagination/pagination_controller.cc

@@ -13,7 +13,7 @@ namespace ash {
 namespace {
 
 // Constants for dealing with scroll events.
-const int kMinScrollToSwitchPage = 20;
+const int kMinScrollToSwitchPage = 10;
 const int kMinHorizVelocityToSwitchPage = 800;
 
 const double kFinishTransitionThreshold = 0.33;