Report precise number of incrementally marked bytes to gc tracer.

src/gc-tracer.h

 // Copyright 2014 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.
 
 #ifndef V8_GC_TRACER_H_
 #define V8_GC_TRACER_H_
 
 namespace v8 {
 namespace internal {
 
@@ skipping 234 matching lines @@
   // Compute the mean step duration of the last incremental marking round.
   // Returns 0 if no incremental marking round has been completed.
   double MeanIncrementalMarkingDuration() const;
 
   // Compute the max step duration of the last incremental marking round.
   // Returns 0 if no incremental marking round has been completed.
   double MaxIncrementalMarkingDuration() const;
 
   // Compute the average incremental marking speed in bytes/second. Returns 0 if
   // no events have been recorded.
-  intptr_t MarkingSpeedInBytesPerMillisecond() const;
+  intptr_t IncrementalMarkingSpeedInBytesPerMillisecond() const;
 
  private:
   // Print one detailed trace line in name=value format.
   // TODO(ernstm): Move to Heap.
   void PrintNVP() const;
 
   // Print one trace line.
   // TODO(ernstm): Move to Heap.
   void Print() const;
 
@@ skipping 34 matching lines @@
 
   // Longest incremental marking step since start of marking.
   double longest_incremental_marking_step_;
 
   DISALLOW_COPY_AND_ASSIGN(GCTracer);
 };
 }
 }  // namespace v8::internal
 
 #endif  // V8_GC_TRACER_H_