Do 2 GCs on LowMemoryNotification instead of 7.

src/heap-inl.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 756 matching lines @@
 }
 
 
 DisallowAllocationFailure::~DisallowAllocationFailure() {
 #ifdef DEBUG
   HEAP->disallow_allocation_failure_ = old_state_;
 #endif
 }
 
 
+FlushEagerly::FlushEagerly() {
+  old_state_ = HEAP->flush_eagerly();
+  HEAP->set_flush_eagerly(true);
+}
+
+
+FlushEagerly::~FlushEagerly() {
+  HEAP->set_flush_eagerly(old_state_);
+}
+
+
 #ifdef DEBUG
 AssertNoAllocation::AssertNoAllocation() {
   Isolate* isolate = ISOLATE;
   active_ = !isolate->optimizing_compiler_thread()->IsOptimizerThread();
   if (active_) {
     old_state_ = isolate->heap()->allow_allocation(false);
   }
 }
 
 
@@ skipping 21 matching lines @@
 AssertNoAllocation::~AssertNoAllocation() { }
 DisableAssertNoAllocation::DisableAssertNoAllocation() { }
 DisableAssertNoAllocation::~DisableAssertNoAllocation() { }
 
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_INL_H_