Revert "Track history of events in GCTracer."

src/incremental-marking.cc

Index: src/incremental-marking.cc
diff --git a/src/incremental-marking.cc b/src/incremental-marking.cc
index 1160032ccfdabca44f1452181d22f7a693d4fc4f..91a9abbf32c27bbdb72b97f819c53d92e3736919 100644
--- a/src/incremental-marking.cc
+++ b/src/incremental-marking.cc
@@ -22,14 +22,17 @@ IncrementalMarking::IncrementalMarking(Heap* heap)
       marking_deque_memory_(NULL),
       marking_deque_memory_committed_(false),
       steps_count_(0),
+      steps_took_(0),
+      longest_step_(0.0),
       old_generation_space_available_at_start_of_incremental_(0),
       old_generation_space_used_at_start_of_incremental_(0),
+      steps_count_since_last_gc_(0),
+      steps_took_since_last_gc_(0),
       should_hurry_(false),
       marking_speed_(0),
       allocated_(0),
       no_marking_scope_depth_(0),
-      unscanned_bytes_of_large_object_(0) {
-}
+      unscanned_bytes_of_large_object_(0) {}
 
 
 void IncrementalMarking::TearDown() {
@@ -655,6 +658,9 @@ void IncrementalMarking::UpdateMarkingDequeAfterScavenge() {
     }
   }
   marking_deque_.set_top(new_top);
+
+  steps_took_since_last_gc_ = 0;
+  steps_count_since_last_gc_ = 0;
 }
 
 
@@ -889,6 +895,7 @@ void IncrementalMarking::Step(intptr_t allocated_bytes,
   }
 
   steps_count_++;
+  steps_count_since_last_gc_++;
 
   bool speed_up = false;
 
@@ -957,7 +964,9 @@ void IncrementalMarking::Step(intptr_t allocated_bytes,
       FLAG_print_cumulative_gc_stat) {
     double end = base::OS::TimeCurrentMillis();
     double delta = (end - start);
-    heap_->tracer()->AddIncrementalMarkingStep(delta);
+    longest_step_ = Max(longest_step_, delta);
+    steps_took_ += delta;
+    steps_took_since_last_gc_ += delta;
     heap_->AddMarkingTime(delta);
   }
 }
@@ -965,10 +974,14 @@ void IncrementalMarking::Step(intptr_t allocated_bytes,
 
 void IncrementalMarking::ResetStepCounters() {
   steps_count_ = 0;
+  steps_took_ = 0;
+  longest_step_ = 0.0;
   old_generation_space_available_at_start_of_incremental_ =
       SpaceLeftInOldSpace();
   old_generation_space_used_at_start_of_incremental_ =
       heap_->PromotedTotalSize();
+  steps_count_since_last_gc_ = 0;
+  steps_took_since_last_gc_ = 0;
   bytes_rescanned_ = 0;
   marking_speed_ = kInitialMarkingSpeed;
   bytes_scanned_ = 0;