Update the Idle collector to do a full GC

src/heap.h

Index: src/heap.h
===================================================================
--- src/heap.h	(revision 2740)
+++ src/heap.h	(working copy)
@@ -629,7 +629,7 @@
 
   // Performs a full garbage collection. Force compaction if the
   // parameter is true.
-  static void CollectAllGarbage(bool force_compaction = false);
+  static void CollectAllGarbage(bool force_compaction);
 
   // Performs a full garbage collection if a context has been disposed
   // since the last time the check was performed.
@@ -839,6 +839,33 @@
            > old_gen_allocation_limit_;
   }
 
+  // Can be called when the embedding application is idle.
+  static bool IdleNotification() {
+    static const int kIdlesBeforeCollection = 7;
+    static int number_idle_notifications = 0;
+    static int last_gc_count = gc_count_;
+
+    bool finished = false;
+
+    if (last_gc_count == gc_count_) {
+      number_idle_notifications++;
+    } else {
+      number_idle_notifications = 0;
+      last_gc_count = gc_count_;
+    }
+
+    if (number_idle_notifications >= kIdlesBeforeCollection) {
+      bool force_compaction = true;
+      CollectAllGarbage(force_compaction);
+      number_idle_notifications = 0;
+      finished = true;
+    }
+
+    // Uncommit unused memory in new space.
+    Heap::UncommitFromSpace();
+    return finished;
+  }
+
  private:
   static int semispace_size_;
   static int initial_semispace_size_;