Feature to run tasks by batches to reduce the overhead of MessagePump

Experiment running tasks in queue for 8ms before before sending a system message.

Bug: 1299950
Change-Id: Ibd82ff03a41ff826e671780451d703a1d71062c7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3594199
Reviewed-by: Francois Pierre Doray <[email protected]>
Reviewed-by: Stephen Nusko <[email protected]>
Commit-Queue: Alex Attar <[email protected]>
Reviewed-by: Gabriel Charette <[email protected]>
Cr-Commit-Position: refs/heads/main@{#1005763}
diff --git a/base/task/task_features.h b/base/task/task_features.h
index 7458a9f9..66d1266 100644
--- a/base/task/task_features.h
+++ b/base/task/task_features.h
@@ -84,6 +84,9 @@
 // based on explicit DelayPolicy rather than based on a threshold.
 extern const BASE_EXPORT base::Feature kExplicitHighResolutionTimerWin;
 
+// Feature to run tasks by batches before pumping out messages.
+extern const BASE_EXPORT base::Feature kRunTasksByBatches;
+
 }  // namespace base
 
 #endif  // BASE_TASK_TASK_FEATURES_H_