Try to fix compile error on Windows.

src/incremental-marking.cc

 // Copyright 2011 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 824 matching lines @@
       (heap_->PromotedTotalSize() >
        (allocation_marking_factor_ + 1) *
            old_generation_space_used_at_start_of_incremental_);
   if (size_of_old_space_multiplied_by_n_during_marking) {
     speed_up = true;
     if (FLAG_trace_gc) {
       PrintF("Speed up marking because of heap size increase\n");
     }
   }
 
-  intptr_t promoted_during_marking = heap_->PromotedTotalSize()
+  int64_t promoted_during_marking = heap_->PromotedTotalSize()
       - old_generation_space_used_at_start_of_incremental_;
   intptr_t delay = allocation_marking_factor_ * MB;
   intptr_t scavenge_slack = heap_->MaxSemiSpaceSize();
 
   // We try to scan at at least twice the speed that we are allocating.
   if (promoted_during_marking > bytes_scanned_ / 2 + scavenge_slack + delay) {
     if (FLAG_trace_gc) {
       PrintF("Speed up marking because marker was not keeping up\n");
     }
     speed_up = true;
@@ skipping 39 matching lines @@
   allocation_marking_factor_ = kInitialAllocationMarkingFactor;
   bytes_scanned_ = 0;
 }
 
 
 int64_t IncrementalMarking::SpaceLeftInOldSpace() {
   return heap_->MaxOldGenerationSize() - heap_->PromotedSpaceSize();
 }
 
 } }  // namespace v8::internal