Allow IdleNotification to trigger Scavenges.

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

Index: src/heap/gc-idle-time-handler.h
diff --git a/src/heap/gc-idle-time-handler.h b/src/heap/gc-idle-time-handler.h
index b0bdce66143c818983b3849992a2efd01f2b9038..09050a279726563a0820c43da1984758990ae0cc 100644
--- a/src/heap/gc-idle-time-handler.h
+++ b/src/heap/gc-idle-time-handler.h
@@ -98,6 +98,14 @@ class GCIdleTimeHandler {
   // Number of scavenges that will trigger start of new idle round.
   static const int kIdleScavengeThreshold;
 
+  // If less than that much memory is left in the new space, we consider it
+  // as almost full and force a new space collection earlier in the idle time.
+  static const size_t kNewSpaceAlmostFullTreshold = 100 * KB;
+
+  // If we haven't recorded any scavenger events yet, we use a conservative
+  // lower bound for the scavenger speed.
+  static const size_t kInitialConservativeScavengeSpeed = 100 * KB;
+
   struct HeapState {
     int contexts_disposed;
     size_t size_of_objects;
@@ -106,6 +114,9 @@ class GCIdleTimeHandler {
     bool sweeping_in_progress;
     size_t mark_compact_speed_in_bytes_per_ms;
     size_t incremental_marking_speed_in_bytes_per_ms;
+    size_t scavenge_speed_in_bytes_per_ms;
+    size_t available_new_space_memory;
+    size_t new_space_capacity;
   };
 
   GCIdleTimeHandler()
@@ -132,9 +143,12 @@ class GCIdleTimeHandler {
   static size_t EstimateMarkCompactTime(
       size_t size_of_objects, size_t mark_compact_speed_in_bytes_per_ms);
 
+  static size_t EstimateScavengeTime(size_t new_space_size,
+                                     size_t scavenger_speed_in_bytes_per_ms);
+
  private:
   void StartIdleRound() { mark_compacts_since_idle_round_started_ = 0; }
-  bool IsIdleRoundFinished() {
+  bool IsMarkCompactIdleRoundFinished() {
     return mark_compacts_since_idle_round_started_ ==
            kMaxMarkCompactsInIdleRound;
   }