Do full GC for small heaps in idle time handler.

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 8def9005e647b344685050b96c19bac4fa1e3e98..311e39d39c7e8d3080dc55a6f9e161b423525c44 100644
--- a/src/heap/gc-idle-time-handler.cc
+++ b/src/heap/gc-idle-time-handler.cc
@@ -78,9 +78,12 @@ GCIdleTimeAction GCIdleTimeHandler::Compute(size_t idle_time_in_ms,
     }
   }
   if (heap_state.incremental_marking_stopped) {
+    const size_t kSmallHeap = 2 * kPointerSize * MB;

[Hannes Payer (out of office), 2014/09/11 09:21:59]

please move this constant to the header file.

     if (idle_time_in_ms >= EstimateMarkCompactTime(
                                heap_state.size_of_objects,
-                               heap_state.mark_compact_speed_in_bytes_per_ms)) {
+                               heap_state.mark_compact_speed_in_bytes_per_ms) ||
+        (heap_state.size_of_objects < kSmallHeap &&
+         heap_state.contexts_disposed > 0)) {
       // If there are no more than two GCs left in this idle round and we are
       // allowed to do a full GC, then make those GCs full in order to compact
       // the code space.