Allow more scavenges in idle notification by increasing the new space limit distance.

src/heap/gc-idle-time-handler.cc

Index: src/heap/gc-idle-time-handler.cc
diff --git a/src/heap/gc-idle-time-handler.cc b/src/heap/gc-idle-time-handler.cc
index 80417a7f25dcf81c20ebf6b8916f3855a82f5278..c2ece17d2ca177e6bddf01e552b77581cb365087 100644
--- a/src/heap/gc-idle-time-handler.cc
+++ b/src/heap/gc-idle-time-handler.cc
@@ -132,8 +132,12 @@ bool GCIdleTimeHandler::ShouldDoScavenge(
         static_cast<size_t>(new_space_size * kConservativeTimeRatio);
   } else {
     // We have to trigger scavenge before we reach the end of new space.
-    new_space_allocation_limit -=
-        new_space_allocation_throughput_in_bytes_per_ms * kMaxScheduledIdleTime;
+    size_t adjust_limit = new_space_allocation_throughput_in_bytes_per_ms *
+                          kMaxScheduledIdleTime * 2;

[rmcilroy, 2015/03/27 15:07:50]

Pull out 'kMaxScheduledIdleTime * 2' as a variable named something like
estimated_time_till_next_idle_notification or similar and add a comment you are
estimating that it will be 2 * frame time since we might miss an idle period (or
whatever your reasoning for this is).

[Hannes Payer (out of office), 2015/03/30 11:07:15]

Done.

+    if (adjust_limit > new_space_allocation_limit)
+      new_space_allocation_limit = 0;
+    else
+      new_space_allocation_limit -= adjust_limit;
   }
 
   if (scavenge_speed_in_bytes_per_ms == 0) {