cc: Remove unused metrics from RenderingStats.

cc/resources/picture.cc

Index: cc/resources/picture.cc
diff --git a/cc/resources/picture.cc b/cc/resources/picture.cc
index 32cce03e748d0a444a8bd4bd18e3d39240734cae..e9b41fddbef453ae2c0ebcfba58e55e11a1edb54 100644
--- a/cc/resources/picture.cc
+++ b/cc/resources/picture.cc
@@ -14,7 +14,6 @@
 #include "cc/base/math_util.h"
 #include "cc/base/util.h"
 #include "cc/debug/benchmark_instrumentation.h"
-#include "cc/debug/rendering_stats_instrumentation.h"
 #include "cc/debug/traced_picture.h"
 #include "cc/debug/traced_value.h"
 #include "cc/layers/content_layer_client.h"
@@ -242,8 +241,7 @@ void Picture::Record(ContentLayerClient* painter,
 }
 
 void Picture::GatherPixelRefs(
-    const SkTileGridPicture::TileGridInfo& tile_grid_info,
-    RenderingStatsInstrumentation* stats_instrumentation) {
+    const SkTileGridPicture::TileGridInfo& tile_grid_info) {
   TRACE_EVENT2("cc", "Picture::GatherPixelRefs",
                "width", layer_rect_.width(),
                "height", layer_rect_.height());
@@ -262,8 +260,6 @@ void Picture::GatherPixelRefs(
   int max_x = 0;
   int max_y = 0;
 
-  base::TimeTicks start_time = stats_instrumentation->StartRecording();
-
   skia::LazyPixelRefList pixel_refs;
   skia::LazyPixelRefUtils::GatherPixelRefs(picture_.get(), &pixel_refs);
   for (skia::LazyPixelRefList::const_iterator it = pixel_refs.begin();
@@ -293,9 +289,6 @@ void Picture::GatherPixelRefs(
     max_y = std::max(max_y, max.y());
   }
 
-  base::TimeDelta duration = stats_instrumentation->EndRecording(start_time);
-  stats_instrumentation->AddImageGathering(duration);
-
   min_pixel_cell_ = gfx::Point(min_x, min_y);
   max_pixel_cell_ = gfx::Point(max_x, max_y);
 }