Perform scavenge in idle tasks.

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index 8f75d5fd630b1a7c627de902d79850807b23845a..9c9a71dc6b88b4493a91f9cb46eb498c6ebed3c4 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -1557,6 +1557,7 @@ bool NewSpace::EnsureAllocation(int size_in_bytes,
     // the new limit accordingly.
     Address new_top = old_top + aligned_size_in_bytes;
     int bytes_allocated = static_cast<int>(new_top - top_on_previous_step_);
+    heap()->ScheduleIdleScavenge(bytes_allocated);

[Hannes Payer (out of office), 2015/09/21 09:00:57]

Hmm, when incremental marking is on, steps will be really small and we are going
to trigger many idle tasks for scavenge. I don't think we should do that. Can we
just invoke this method on ScavengeJob::kBytesAllocatedBeforeNextIdleTask
allocations? WDYT?

[ulan, 2015/09/23 09:58:38]

The function already checks the bytes allocated. Changed the name accordingly.

     heap()->incremental_marking()->Step(bytes_allocated,
                                         IncrementalMarking::GC_VIA_STACK_GUARD);
     UpdateInlineAllocationLimit(aligned_size_in_bytes);