Clean-up and repair cumulative marking and sweeping time stats.

src/gc-tracer.h

Index: src/gc-tracer.h
diff --git a/src/gc-tracer.h b/src/gc-tracer.h
index 0f4f135256ecc6ebd0ca0ea68ba1b68bf299108a..2f4c626cd1cbe06e418e64af03a13d1298a12a1c 100644
--- a/src/gc-tracer.h
+++ b/src/gc-tracer.h
@@ -220,6 +220,26 @@ class GCTracer BASE_EMBEDDED {
   // Log an incremental marking step.
   void AddIncrementalMarkingStep(double duration, intptr_t bytes);
 
+  // Log time spent in marking.
+  void AddMarkingTime(double duration) {
+    cumulative_marking_duration_ += duration;
+  }
+
+  // Time spent in marking.
+  double cumulative_marking_duration() const {
+    return cumulative_marking_duration_;
+  }
+
+  // Log time spent in sweeping on main thread.
+  void AddSweepingTime(double duration) {
+    cumulative_sweeping_duration_ += duration;
+  }
+
+  // Time spent in sweeping on main thread.
+  double cumulative_sweeping_duration() const {
+    return cumulative_sweeping_duration_;
+  }
+
   // Compute the mean duration of the last scavenger events. Returns 0 if no
   // events have been recorded.
   double MeanScavengerDuration() const {
@@ -301,6 +321,19 @@ class GCTracer BASE_EMBEDDED {
   // Longest incremental marking step since start of marking.
   double longest_incremental_marking_step_;
 
+  // Total marking time.
+  // This timer is precise when run with --print-cumulative-gc-stat
+  double cumulative_marking_duration_;
+
+  // Total sweeping time on the main thread.
+  // This timer is precise when run with --print-cumulative-gc-stat
+  // TODO(hpayer): Account for sweeping time on sweeper threads. Add a
+  // different field for that.
+  // TODO(hpayer): This timer right now just holds the sweeping time
+  // of the initial atomic sweeping pause. Make sure that it accumulates
+  // all sweeping operations performed on the main thread.
+  double cumulative_sweeping_duration_;
+
   DISALLOW_COPY_AND_ASSIGN(GCTracer);
 };
 }