[heap] Fix comment in tracer.

src/heap/gc-tracer.h

Index: src/heap/gc-tracer.h
diff --git a/src/heap/gc-tracer.h b/src/heap/gc-tracer.h
index e4751c84184ece1612a29e154a2e7bb457439d20..7572059dc980626c696b6ab9f15e749b9d94a292 100644
--- a/src/heap/gc-tracer.h
+++ b/src/heap/gc-tracer.h
@@ -419,13 +419,13 @@ class GCTracer {
   // Returns 0 if no allocation events have been recorded.
   size_t AllocationThroughputInBytesPerMillisecond(double time_ms) const;
 
-  // Allocation throughput in heap in bytes/milliseconds in
-  // the last five seconds.
+  // Allocation throughput in heap in bytes/milliseconds in the last
+  // kThroughputTimeFrameMs seconds.
   // Returns 0 if no allocation events have been recorded.
   size_t CurrentAllocationThroughputInBytesPerMillisecond() const;
 
-  // Allocation throughput in old generation in bytes/milliseconds in
-  // the last five seconds.
+  // Allocation throughput in old generation in bytes/milliseconds in the last
+  // kThroughputTimeFrameMs seconds.
   // Returns 0 if no allocation events have been recorded.
   size_t CurrentOldGenerationAllocationThroughputInBytesPerMillisecond() const;