[heap] Add GC accounting to slow allocation and incremental marking job

src/heap/spaces.cc

Index: src/heap/spaces.cc
diff --git a/src/heap/spaces.cc b/src/heap/spaces.cc
index 371dfb1e5627b403886d4d292f782debb630d5cf..e3d2f81ea2db0af54dca0799d2ceeb99a4abc986 100644
--- a/src/heap/spaces.cc
+++ b/src/heap/spaces.cc
@@ -2896,10 +2896,12 @@ HeapObject* CompactionSpace::SweepAndRetryAllocation(int size_in_bytes) {
 }
 
 HeapObject* PagedSpace::SlowAllocateRaw(int size_in_bytes) {
+  // Allocation in this space has failed.
   DCHECK_GE(size_in_bytes, 0);
   const int kMaxPagesToSweep = 1;
 
-  // Allocation in this space has failed.
+  VMState<GC> state(heap()->isolate());

[Michael Lippautz, 2017/05/03 15:44:52]

I think this is a pretty good estimate here that avoids polluting the fast path.
wdyt?

+  RuntimeCallTimerScope(heap()->isolate(), &RuntimeCallStats::GC);
 
   MarkCompactCollector* collector = heap()->mark_compact_collector();
   // Sweeping is still in progress.