cc: Add UMA stats for record and raster time.

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 1b814477b427f3324d0f5b9048187d5c658e949a..f50bced37856f60a83872cd0c4b757195e74051c 100644
--- a/cc/resources/picture_pile.cc
+++ b/cc/resources/picture_pile.cc
@@ -8,6 +8,7 @@
 #include <limits>
 #include <vector>
 
+#include "cc/base/histogram_macros.h"
 #include "cc/base/region.h"
 #include "cc/resources/picture_pile_impl.h"
 #include "skia/ext/analysis_canvas.h"
@@ -149,6 +150,11 @@ const bool kDefaultClearCanvasSetting = false;
 const bool kDefaultClearCanvasSetting = true;
 #endif
 
+DEFINE_SCOPED_UMA_HISTOGRAM_AREA_TIMER(
+    ScopedPicturePileUpdateTimer,
+    "Renderer4.PicturePileUpdateUs",
+    "Renderer4.PicturePileUpdatePixelsPerMs");
+
 }  // namespace
 
 namespace cc {
@@ -181,6 +187,8 @@ bool PicturePile::UpdateAndExpandInvalidation(
     const gfx::Rect& visible_layer_rect,
     int frame_number,
     RecordingSource::RecordingMode recording_mode) {
+  ScopedPicturePileUpdateTimer timer;
+
   gfx::Rect interest_rect = visible_layer_rect;
   interest_rect.Inset(-pixel_record_distance_, -pixel_record_distance_);
   recorded_viewport_ = interest_rect;
@@ -197,6 +205,10 @@ bool PicturePile::UpdateAndExpandInvalidation(
   if (record_rects.empty())
     return updated;
 
+  // Count the area that is being recorded.
+  for (const auto& record_rect : record_rects)
+    timer.AddArea(record_rect.size().GetArea());
+
   CreatePictures(painter, recording_mode, record_rects);
 
   DetermineIfSolidColor();