Pass GC flags to incremental marker and start incremental marking with

src/heap/heap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 4632 matching lines @@
                                  GCIdleTimeHandler::HeapState heap_state,
                                  double deadline_in_ms,
                                  bool is_long_idle_notification) {
   bool result = false;
   switch (action.type) {
     case DONE:
       result = true;
       break;
     case DO_INCREMENTAL_MARKING: {
       if (incremental_marking()->IsStopped()) {
-        // TODO(ulan): take reduce_memory into account.
-        incremental_marking()->Start();
+        incremental_marking()->Start(
+            action.reduce_memory ? kReduceMemoryFootprintMask : kNoGCFlags);
       }
       double remaining_idle_time_in_ms = 0.0;
       do {
         incremental_marking()->Step(
             action.parameter, IncrementalMarking::NO_GC_VIA_STACK_GUARD,
             IncrementalMarking::FORCE_MARKING,
             IncrementalMarking::DO_NOT_FORCE_COMPLETION);
         remaining_idle_time_in_ms =
             deadline_in_ms - MonotonicallyIncreasingTimeInMs();
       } while (remaining_idle_time_in_ms >=
@@ skipping 1922 matching lines @@
     *object_type = "CODE_TYPE";                                                \
     *object_sub_type = "CODE_AGE/" #name;                                      \
     return true;
     CODE_AGE_LIST_COMPLETE(COMPARE_AND_RETURN_NAME)
 #undef COMPARE_AND_RETURN_NAME
   }
   return false;
 }
 }
 }  // namespace v8::internal