Move idle notification handling to GCIdleTimeHandler.

src/heap/gc-tracer.cc

Index: src/heap/gc-tracer.cc
diff --git a/src/heap/gc-tracer.cc b/src/heap/gc-tracer.cc
index a0f1c464cc26f33d1dae45c36a1f5ac76a606a6c..7e81777038a5b6ed2d41199cce551b3151ebb4a7 100644
--- a/src/heap/gc-tracer.cc
+++ b/src/heap/gc-tracer.cc
@@ -418,5 +418,21 @@ intptr_t GCTracer::ScavengeSpeedInBytesPerMillisecond() const {
 
   return static_cast<intptr_t>(bytes / durations);
 }
+
+
+intptr_t GCTracer::MaxMarkSweepSpeedInBytesPerMillisecond() const {
+  intptr_t speed = 0;
+  EventBuffer::const_iterator iter = mark_compactor_events_.begin();
+  while (iter != mark_compactor_events_.end()) {
+    intptr_t bytes = iter->new_space_object_size;
+    double duration = iter->end_time - iter->start_time;
+    if (duration > 0) {
+      intptr_t current_speed = static_cast<intptr_t>(bytes / duration);
+      speed = Max(speed, current_speed);
+    }
+    ++iter;
+  }
+  return speed;
+}
 }
 }  // namespace v8::internal