m115: Fix fling requesting unnecessary ticks

GenerateAndSendFlingProgressEvents can recursveily call StopFling, so
need to check `fling_curve_` again before requesting another tick.

(cherry picked from commit 20600d1)

Bug: 1450898
Change-Id: I38ea1f4eec7b8cefbbcf6b6f7483b1e65c28b8f7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4584094
Reviewed-by: David Bokan <bokan@chromium.org>
Commit-Queue: Bo Liu <boliu@chromium.org>
Cr-Original-Commit-Position: refs/heads/main@{#1153214}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4599047
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/branch-heads/5790@{#455}
Cr-Branched-From: 1d71a33-refs/heads/main@{#1148114}

content/browser/renderer_host/input/fling_controller.cc

@@ -249,7 +249,9 @@ void FlingController::ProgressFling(base::TimeTicks current_time) {
 
   // As long as the fling curve is active, the fling progress must get
   // scheduled even when the last delta to scroll was zero.
-  ScheduleFlingProgress();
+  if (fling_curve_) {
+    ScheduleFlingProgress();
+  }
 }
 
 void FlingController::StopFling() {