Revert accidental commit that messed up the incremental speed heuristics.

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 813 matching lines @@
     speed_up = true;
     old_generation_space_used_at_start_of_incremental_ =
         heap_->PromotedTotalSize();
   }
 
   if ((steps_count_ % kAllocationMarkingFactorSpeedupInterval) == 0 &&
       allocation_marking_factor_ < kMaxAllocationMarkingFactor) {
     speed_up = true;
   }
 
-  if (speed_up && 0) {
+  if (speed_up) {
     allocation_marking_factor_ += kAllocationMarkingFactorSpeedup;
     allocation_marking_factor_ =
         static_cast<int>(allocation_marking_factor_ * 1.3);
     if (FLAG_trace_gc) {
       PrintF("Marking speed increased to %d\n", allocation_marking_factor_);
     }
   }
 
   if (FLAG_trace_incremental_marking || FLAG_trace_gc) {
     double end = OS::TimeCurrentMillis();
@@ skipping 18 matching lines @@
   bytes_rescanned_ = 0;
   allocation_marking_factor_ = kInitialAllocationMarkingFactor;
 }
 
 
 int64_t IncrementalMarking::SpaceLeftInOldSpace() {
   return heap_->MaxOldGenerationSize() - heap_->PromotedSpaceSize();
 }
 
 } }  // namespace v8::internal