cc: Add best_record_time to rendering stats.

cc/resources/picture_pile.cc

Index: cc/resources/picture_pile.cc
diff --git a/cc/resources/picture_pile.cc b/cc/resources/picture_pile.cc
index 17283ddd2631f71a208b27633de1eb5dc6c2409f..2eac495dcbfd8de8b2722c3cbc9dca8077d25925 100644
--- a/cc/resources/picture_pile.cc
+++ b/cc/resources/picture_pile.cc
@@ -5,10 +5,12 @@
 #include "cc/resources/picture_pile.h"
 
 #include <algorithm>
+#include <limits>
 #include <vector>
 
 #include "cc/base/region.h"
 #include "cc/debug/benchmark_instrumentation.h"
+#include "cc/debug/rendering_stats_instrumentation.h"
 #include "cc/resources/picture_pile_impl.h"
 
 namespace {
@@ -114,8 +116,23 @@ bool PicturePile::Update(
         modified_pile = true;
         TRACE_EVENT0(benchmark_instrumentation::kCategory,
                      benchmark_instrumentation::kRecordLoop);
-        for (int i = 0; i < repeat_count; i++)
-          (*pic)->Record(painter, tile_grid_info_, stats_instrumentation);
+        base::TimeDelta total_duration =
+          base::TimeDelta::FromInternalValue(0);
+        base::TimeDelta best_duration = base::TimeDelta::FromInternalValue(
+            std::numeric_limits<int64>::max());
+        for (int i = 0; i < repeat_count; i++) {
+          base::TimeTicks start_time = stats_instrumentation->StartRecording();
+          (*pic)->Record(painter, tile_grid_info_);
+          base::TimeDelta duration =
+              stats_instrumentation->EndRecording(start_time);
+          total_duration += duration;
+          best_duration = std::min(duration, best_duration);
+        }
+        int painted_pixels =
+            (*pic)->LayerRect().width() * (*pic)->LayerRect().height();
+        stats_instrumentation->AddRecord(total_duration,
+                                         best_duration,
+                                         painted_pixels);
         (*pic)->GatherPixelRefs(tile_grid_info_, stats_instrumentation);
         (*pic)->CloneForDrawing(num_raster_threads_);
       }