Make transition to reduce memory mode more conservative in idle time handler.

test/unittests/heap/gc-idle-time-handler-unittest.cc

Index: test/unittests/heap/gc-idle-time-handler-unittest.cc
diff --git a/test/unittests/heap/gc-idle-time-handler-unittest.cc b/test/unittests/heap/gc-idle-time-handler-unittest.cc
index 67ae4e05ce0d83bf43e2e96363ddd68512f8a747..f421f002f915c924b30340566b315bbd95b3df1d 100644
--- a/test/unittests/heap/gc-idle-time-handler-unittest.cc
+++ b/test/unittests/heap/gc-idle-time-handler-unittest.cc
@@ -94,7 +94,7 @@ class GCIdleTimeHandlerTest : public ::testing::Test {
   static const size_t kScavengeSpeed = 100 * KB;
   static const size_t kNewSpaceCapacity = 1 * MB;
   static const size_t kNewSpaceAllocationThroughput = 10 * KB;
-  static const int kMaxNotifications = 100;
+  static const int kMaxNotifications = 1000;
 
  private:
   GCIdleTimeHandler handler_;