Revert 201498 "Add devtools instrumentation for canvas creation ..."

This is a speculative revert to try and fix build breakage starting with:
http://build.chromium.org/p/chromium.linux/builders/Android%20Tests%20%28dbg%29/builds/10905

If it doesn't help, this revert should be reverted :-)

> Add devtools instrumentation for canvas creation in BitmapContentLayerUpdater
> 
> Canvas bitmap allocation may take considerable time (close to that of
> actual layer update), so having it intrumented helps to reduce "unknown"
> time on Timeline.
> 
> - keep layer id in content layer updater, plumb it through all
>     content layer updaters.
> - extract boilerplate of devtools instrumentation classes to a macro;
> - add instrumentation around canvas bitmap allocation in
>     BitmapContentLayerUpdater.
> 
> Related blink change: https://codereview.chromium.org/15466005
> 
> R=nduca@chromium.org
> 
> Review URL: https://codereview.chromium.org/15317008

TBR=caseq@google.com

Review URL: https://codereview.chromium.org/15697005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@201510 0039d316-1c4b-4281-b951-d872f2087c98

17 files changed, 70 insertions, 96 deletions

diff --git a/cc/debug/devtools_instrumentation.h b/cc/debug/devtools_instrumentation.h
index 7b2ea1a..eb5a619 100644
--- a/cc/debug/devtools_instrumentation.h
+++ b/cc/debug/devtools_instrumentation.h
@@ -13,25 +13,45 @@ namespace devtools_instrumentation {
 namespace internal {
 const char kCategory[] = "cc,devtools";
 const char kLayerId[] = "layerId";
-}
-
 const char kPaintLayer[] = "PaintLayer";
 const char kRasterTask[] = "RasterTask";
 const char kImageDecodeTask[] = "ImageDecodeTask";
-const char kPaintSetup[] = "PaintSetup";
+}
 
-class ScopedLayerTask {
- public:
-  explicit ScopedLayerTask(const char* event_name, int layer_id)
-    : event_name_(event_name) {
-    TRACE_EVENT_BEGIN1(internal::kCategory, event_name_,
+struct ScopedPaintLayer {
+  explicit ScopedPaintLayer(int layer_id) {
+    TRACE_EVENT_BEGIN1(internal::kCategory, internal::kPaintLayer,
         internal::kLayerId, layer_id);
   }
-  ~ScopedLayerTask() {
-    TRACE_EVENT_END0(internal::kCategory, event_name_);
+  ~ScopedPaintLayer() {
+    TRACE_EVENT_END0(internal::kCategory, internal::kPaintLayer);
   }
- private:
-  const char* event_name_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedPaintLayer);
+};
+
+struct ScopedRasterTask {
+  explicit ScopedRasterTask(int layer_id) {
+    TRACE_EVENT_BEGIN1(internal::kCategory, internal::kRasterTask,
+        internal::kLayerId, layer_id);
+  }
+  ~ScopedRasterTask() {
+    TRACE_EVENT_END0(internal::kCategory, internal::kRasterTask);
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedRasterTask);
+};
+
+struct ScopedImageDecodeTask {
+  explicit ScopedImageDecodeTask(int layer_id) {
+    TRACE_EVENT_BEGIN1(internal::kCategory, internal::kImageDecodeTask,
+        internal::kLayerId, layer_id);
+  }
+  ~ScopedImageDecodeTask() {
+    TRACE_EVENT_END0(internal::kCategory, internal::kImageDecodeTask);
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(ScopedImageDecodeTask);
 };
 
 struct ScopedLayerObjectTracker
@@ -50,3 +70,4 @@ struct ScopedLayerObjectTracker
 }  // namespace cc
 
 #endif  // CC_DEBUG_DEVTOOLS_INSTRUMENTATION_H_
+
diff --git a/cc/layers/content_layer.cc b/cc/layers/content_layer.cc
index 44af47e..a6aa5ba 100644
--- a/cc/layers/content_layer.cc
+++ b/cc/layers/content_layer.cc
@@ -98,18 +98,15 @@ void ContentLayer::CreateUpdaterIfNeeded() {
   if (layer_tree_host()->settings().accelerate_painting)
     updater_ = SkPictureContentLayerUpdater::Create(
         painter.Pass(),
-        rendering_stats_instrumentation(),
-        id());
+        rendering_stats_instrumentation());
   else if (layer_tree_host()->settings().per_tile_painting_enabled)
     updater_ = BitmapSkPictureContentLayerUpdater::Create(
         painter.Pass(),
-        rendering_stats_instrumentation(),
-        id());
+        rendering_stats_instrumentation());
   else
     updater_ = BitmapContentLayerUpdater::Create(
         painter.Pass(),
-        rendering_stats_instrumentation(),
-        id());
+        rendering_stats_instrumentation());
   updater_->SetOpaque(contents_opaque());
 
   unsigned texture_format =
diff --git a/cc/layers/content_layer_unittest.cc b/cc/layers/content_layer_unittest.cc
index e9faa7d..16e42ed 100644
--- a/cc/layers/content_layer_unittest.cc
+++ b/cc/layers/content_layer_unittest.cc
@@ -42,8 +42,7 @@ TEST(ContentLayerTest, ContentLayerPainterWithDeviceScale) {
   scoped_refptr<BitmapContentLayerUpdater> updater =
       BitmapContentLayerUpdater::Create(
           ContentLayerPainter::Create(&client).PassAs<LayerPainter>(),
-          &stats_instrumentation,
-          0);
+          &stats_instrumentation);
 
   gfx::Rect resulting_opaque_rect;
   updater->PrepareToUpdate(content_rect,
diff --git a/cc/layers/picture_layer.cc b/cc/layers/picture_layer.cc
index 4f4b385..dfb645f 100644
--- a/cc/layers/picture_layer.cc
+++ b/cc/layers/picture_layer.cc
@@ -89,8 +89,7 @@ void PictureLayer::Update(ResourceUpdateQueue*,
 
   gfx::Rect visible_layer_rect = gfx::ScaleToEnclosingRect(
       visible_content_rect(), 1.f / contents_scale_x());
-  devtools_instrumentation::ScopedLayerTask paint_layer(
-      devtools_instrumentation::kPaintLayer, id());
+  devtools_instrumentation::ScopedPaintLayer paint_layer(id());
   pile_->Update(client_,
                 background_color(),
                 pile_invalidation_,
diff --git a/cc/layers/scrollbar_layer.cc b/cc/layers/scrollbar_layer.cc
index ed25d2e..d7c19ff 100644
--- a/cc/layers/scrollbar_layer.cc
+++ b/cc/layers/scrollbar_layer.cc
@@ -1,4 +1,3 @@
-
 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
@@ -272,8 +271,7 @@ void ScrollbarLayer::CreateUpdaterIfNeeded() {
             painter_.get(),
             geometry_.get(),
             WebKit::WebScrollbar::BackTrackPart).PassAs<LayerPainter>(),
-        rendering_stats_instrumentation(),
-        id());
+        rendering_stats_instrumentation());
   }
   if (!back_track_) {
     back_track_ = back_track_updater_->CreateResource(
@@ -290,8 +288,7 @@ void ScrollbarLayer::CreateUpdaterIfNeeded() {
               painter_.get(),
               geometry_.get(),
               WebKit::WebScrollbar::ForwardTrackPart).PassAs<LayerPainter>(),
-          rendering_stats_instrumentation(),
-          id());
+          rendering_stats_instrumentation());
     }
     if (!fore_track_) {
       fore_track_ = fore_track_updater_->CreateResource(
@@ -304,8 +301,7 @@ void ScrollbarLayer::CreateUpdaterIfNeeded() {
         ScrollbarThumbPainter::Create(scrollbar_.get(),
                                       painter_.get(),
                                       geometry_.get()).PassAs<LayerPainter>(),
-        rendering_stats_instrumentation(),
-        id());
+        rendering_stats_instrumentation());
   }
   if (!thumb_) {
     thumb_ = thumb_updater_->CreateResource(
diff --git a/cc/layers/tiled_layer_unittest.cc b/cc/layers/tiled_layer_unittest.cc
index 8274c8b..fb682d4 100644
--- a/cc/layers/tiled_layer_unittest.cc
+++ b/cc/layers/tiled_layer_unittest.cc
@@ -1765,8 +1765,7 @@ class UpdateTrackingTiledLayer : public FakeTiledLayer {
     tracking_layer_painter_ = painter.get();
     layer_updater_ =
         BitmapContentLayerUpdater::Create(painter.PassAs<LayerPainter>(),
-                                          &stats_instrumentation_,
-                                          0);
+                                          &stats_instrumentation_);
   }
 
   TrackingLayerPainter* tracking_layer_painter() const {
diff --git a/cc/resources/bitmap_content_layer_updater.cc b/cc/resources/bitmap_content_layer_updater.cc
index 77ff754..a5684a0 100644
--- a/cc/resources/bitmap_content_layer_updater.cc
+++ b/cc/resources/bitmap_content_layer_updater.cc
@@ -4,7 +4,6 @@
 
 #include "cc/resources/bitmap_content_layer_updater.h"
 
-#include "cc/debug/devtools_instrumentation.h"
 #include "cc/debug/rendering_stats_instrumentation.h"
 #include "cc/resources/layer_painter.h"
 #include "cc/resources/prioritized_resource.h"
@@ -32,19 +31,15 @@ void BitmapContentLayerUpdater::Resource::Update(ResourceUpdateQueue* queue,
 
 scoped_refptr<BitmapContentLayerUpdater> BitmapContentLayerUpdater::Create(
     scoped_ptr<LayerPainter> painter,
-    RenderingStatsInstrumentation* stats_instrumentation,
-    int layer_id) {
+    RenderingStatsInstrumentation* stats_instrumentation) {
   return make_scoped_refptr(
-      new BitmapContentLayerUpdater(painter.Pass(),
-                                    stats_instrumentation,
-                                    layer_id));
+      new BitmapContentLayerUpdater(painter.Pass(), stats_instrumentation));
 }
 
 BitmapContentLayerUpdater::BitmapContentLayerUpdater(
     scoped_ptr<LayerPainter> painter,
-    RenderingStatsInstrumentation* stats_instrumentation,
-    int layer_id)
-    : ContentLayerUpdater(painter.Pass(), stats_instrumentation, layer_id),
+    RenderingStatsInstrumentation* stats_instrumentation)
+    : ContentLayerUpdater(painter.Pass(), stats_instrumentation),
       opaque_(false) {}
 
 BitmapContentLayerUpdater::~BitmapContentLayerUpdater() {}
@@ -62,11 +57,7 @@ void BitmapContentLayerUpdater::PrepareToUpdate(
     float contents_height_scale,
     gfx::Rect* resulting_opaque_rect,
     RenderingStats* stats) {
-  devtools_instrumentation::ScopedLayerTask paint_layer(
-      devtools_instrumentation::kPaintLayer, layer_id_);
   if (canvas_size_ != content_rect.size()) {
-    devtools_instrumentation::ScopedLayerTask paint_setup(
-        devtools_instrumentation::kPaintSetup, layer_id_);
     canvas_size_ = content_rect.size();
     canvas_ = skia::AdoptRef(skia::CreateBitmapCanvas(
         canvas_size_.width(), canvas_size_.height(), opaque_));
diff --git a/cc/resources/bitmap_content_layer_updater.h b/cc/resources/bitmap_content_layer_updater.h
index db270f0..ad739b4 100644
--- a/cc/resources/bitmap_content_layer_updater.h
+++ b/cc/resources/bitmap_content_layer_updater.h
@@ -41,8 +41,7 @@ class CC_EXPORT BitmapContentLayerUpdater : public ContentLayerUpdater {
 
   static scoped_refptr<BitmapContentLayerUpdater> Create(
       scoped_ptr<LayerPainter> painter,
-      RenderingStatsInstrumentation* stats_instrumenation,
-      int layer_id);
+      RenderingStatsInstrumentation* stats_instrumenation);
 
   virtual scoped_ptr<LayerUpdater::Resource> CreateResource(
       PrioritizedResourceManager* manager) OVERRIDE;
@@ -63,8 +62,7 @@ class CC_EXPORT BitmapContentLayerUpdater : public ContentLayerUpdater {
  protected:
   BitmapContentLayerUpdater(
       scoped_ptr<LayerPainter> painter,
-      RenderingStatsInstrumentation* stats_instrumenation,
-      int layer_id);
+      RenderingStatsInstrumentation* stats_instrumenation);
   virtual ~BitmapContentLayerUpdater();
 
   skia::RefPtr<SkCanvas> canvas_;
diff --git a/cc/resources/bitmap_skpicture_content_layer_updater.cc b/cc/resources/bitmap_skpicture_content_layer_updater.cc
index 12a2828..48e67db 100644
--- a/cc/resources/bitmap_skpicture_content_layer_updater.cc
+++ b/cc/resources/bitmap_skpicture_content_layer_updater.cc
@@ -44,21 +44,16 @@ void BitmapSkPictureContentLayerUpdater::Resource::Update(
 scoped_refptr<BitmapSkPictureContentLayerUpdater>
 BitmapSkPictureContentLayerUpdater::Create(
     scoped_ptr<LayerPainter> painter,
-    RenderingStatsInstrumentation* stats_instrumentation,
-    int layer_id) {
+    RenderingStatsInstrumentation* stats_instrumentation) {
   return make_scoped_refptr(
       new BitmapSkPictureContentLayerUpdater(painter.Pass(),
-                                             stats_instrumentation,
-                                             layer_id));
+                                             stats_instrumentation));
 }
 
 BitmapSkPictureContentLayerUpdater::BitmapSkPictureContentLayerUpdater(
     scoped_ptr<LayerPainter> painter,
-    RenderingStatsInstrumentation* stats_instrumentation,
-    int layer_id)
-    : SkPictureContentLayerUpdater(painter.Pass(),
-                                   stats_instrumentation,
-                                   layer_id) {}
+    RenderingStatsInstrumentation* stats_instrumentation)
+    : SkPictureContentLayerUpdater(painter.Pass(), stats_instrumentation) {}
 
 BitmapSkPictureContentLayerUpdater::~BitmapSkPictureContentLayerUpdater() {}
 
diff --git a/cc/resources/bitmap_skpicture_content_layer_updater.h b/cc/resources/bitmap_skpicture_content_layer_updater.h
index c4a73c4..144047b 100644
--- a/cc/resources/bitmap_skpicture_content_layer_updater.h
+++ b/cc/resources/bitmap_skpicture_content_layer_updater.h
@@ -35,8 +35,7 @@ class BitmapSkPictureContentLayerUpdater : public SkPictureContentLayerUpdater {
 
   static scoped_refptr<BitmapSkPictureContentLayerUpdater> Create(
       scoped_ptr<LayerPainter> painter,
-      RenderingStatsInstrumentation* stats_instrumentation,
-      int layer_id);
+      RenderingStatsInstrumentation* stats_instrumentation);
 
   virtual scoped_ptr<LayerUpdater::Resource> CreateResource(
       PrioritizedResourceManager* manager) OVERRIDE;
@@ -47,8 +46,7 @@ class BitmapSkPictureContentLayerUpdater : public SkPictureContentLayerUpdater {
  private:
   BitmapSkPictureContentLayerUpdater(
       scoped_ptr<LayerPainter> painter,
-      RenderingStatsInstrumentation* stats_instrumentation,
-      int layer_id);
+      RenderingStatsInstrumentation* stats_instrumentation);
   virtual ~BitmapSkPictureContentLayerUpdater();
 
   DISALLOW_COPY_AND_ASSIGN(BitmapSkPictureContentLayerUpdater);
diff --git a/cc/resources/caching_bitmap_content_layer_updater.cc b/cc/resources/caching_bitmap_content_layer_updater.cc
index 2efd31d..42e462b 100644
--- a/cc/resources/caching_bitmap_content_layer_updater.cc
+++ b/cc/resources/caching_bitmap_content_layer_updater.cc
@@ -13,21 +13,16 @@ namespace cc {
 scoped_refptr<CachingBitmapContentLayerUpdater>
 CachingBitmapContentLayerUpdater::Create(
     scoped_ptr<LayerPainter> painter,
-    RenderingStatsInstrumentation* stats_instrumentation,
-    int layer_id) {
+    RenderingStatsInstrumentation* stats_instrumentation) {
   return make_scoped_refptr(
       new CachingBitmapContentLayerUpdater(painter.Pass(),
-                                           stats_instrumentation,
-                                           layer_id));
+                                           stats_instrumentation));
 }
 
 CachingBitmapContentLayerUpdater::CachingBitmapContentLayerUpdater(
     scoped_ptr<LayerPainter> painter,
-    RenderingStatsInstrumentation* stats_instrumentation,
-    int layer_id)
-    : BitmapContentLayerUpdater(painter.Pass(),
-                                stats_instrumentation,
-                                layer_id),
+    RenderingStatsInstrumentation* stats_instrumentation)
+    : BitmapContentLayerUpdater(painter.Pass(), stats_instrumentation),
       pixels_did_change_(false) {}
 
 CachingBitmapContentLayerUpdater::~CachingBitmapContentLayerUpdater() {}
diff --git a/cc/resources/caching_bitmap_content_layer_updater.h b/cc/resources/caching_bitmap_content_layer_updater.h
index 33726c8..657ea56 100644
--- a/cc/resources/caching_bitmap_content_layer_updater.h
+++ b/cc/resources/caching_bitmap_content_layer_updater.h
@@ -15,8 +15,7 @@ class CachingBitmapContentLayerUpdater : public BitmapContentLayerUpdater {
  public:
   static scoped_refptr<CachingBitmapContentLayerUpdater> Create(
       scoped_ptr<LayerPainter>,
-      RenderingStatsInstrumentation* stats_instrumentation,
-      int layer_id);
+      RenderingStatsInstrumentation* stats_instrumentation);
 
   virtual void PrepareToUpdate(gfx::Rect content_rect,
                                gfx::Size tile_size,
@@ -32,8 +31,7 @@ class CachingBitmapContentLayerUpdater : public BitmapContentLayerUpdater {
  private:
   CachingBitmapContentLayerUpdater(
       scoped_ptr<LayerPainter> painter,
-      RenderingStatsInstrumentation* stats_instrumentation,
-      int layer_id);
+      RenderingStatsInstrumentation* stats_instrumentation);
   virtual ~CachingBitmapContentLayerUpdater();
 
   bool pixels_did_change_;
diff --git a/cc/resources/content_layer_updater.cc b/cc/resources/content_layer_updater.cc
index e975cd4..4e967e2 100644
--- a/cc/resources/content_layer_updater.cc
+++ b/cc/resources/content_layer_updater.cc
@@ -19,10 +19,8 @@ namespace cc {
 
 ContentLayerUpdater::ContentLayerUpdater(
     scoped_ptr<LayerPainter> painter,
-    RenderingStatsInstrumentation* stats_instrumentation,
-    int layer_id)
+    RenderingStatsInstrumentation* stats_instrumentation)
     : rendering_stats_instrumentation_(stats_instrumentation),
-      layer_id_(layer_id),
       painter_(painter.Pass()) {}
 
 ContentLayerUpdater::~ContentLayerUpdater() {}
diff --git a/cc/resources/content_layer_updater.h b/cc/resources/content_layer_updater.h
index 0b7e163..9176f2c 100644
--- a/cc/resources/content_layer_updater.h
+++ b/cc/resources/content_layer_updater.h
@@ -22,8 +22,7 @@ class RenderingStatsInstrumentation;
 class CC_EXPORT ContentLayerUpdater : public LayerUpdater {
  protected:
   ContentLayerUpdater(scoped_ptr<LayerPainter> painter,
-                      RenderingStatsInstrumentation* stats_instrumentation,
-                      int layer_id);
+                      RenderingStatsInstrumentation* stats_instrumentation);
   virtual ~ContentLayerUpdater();
 
   void PaintContents(SkCanvas* canvas,
@@ -35,7 +34,6 @@ class CC_EXPORT ContentLayerUpdater : public LayerUpdater {
   gfx::Rect content_rect() const { return content_rect_; }
 
   RenderingStatsInstrumentation* rendering_stats_instrumentation_;
-  int layer_id_;
 
  private:
   gfx::Rect content_rect_;
diff --git a/cc/resources/skpicture_content_layer_updater.cc b/cc/resources/skpicture_content_layer_updater.cc
index bfa6d56..5010aa9 100644
--- a/cc/resources/skpicture_content_layer_updater.cc
+++ b/cc/resources/skpicture_content_layer_updater.cc
@@ -31,9 +31,8 @@ void SkPictureContentLayerUpdater::Resource::Update(ResourceUpdateQueue* queue,
 
 SkPictureContentLayerUpdater::SkPictureContentLayerUpdater(
     scoped_ptr<LayerPainter> painter,
-    RenderingStatsInstrumentation* stats_instrumentation,
-    int layer_id)
-    : ContentLayerUpdater(painter.Pass(), stats_instrumentation, layer_id),
+    RenderingStatsInstrumentation* stats_instrumentation)
+    : ContentLayerUpdater(painter.Pass(), stats_instrumentation),
       layer_is_opaque_(false) {}
 
 SkPictureContentLayerUpdater::~SkPictureContentLayerUpdater() {}
@@ -41,12 +40,9 @@ SkPictureContentLayerUpdater::~SkPictureContentLayerUpdater() {}
 scoped_refptr<SkPictureContentLayerUpdater>
 SkPictureContentLayerUpdater::Create(
     scoped_ptr<LayerPainter> painter,
-    RenderingStatsInstrumentation* stats_instrumentation,
-    int layer_id) {
+    RenderingStatsInstrumentation* stats_instrumentation) {
   return make_scoped_refptr(
-      new SkPictureContentLayerUpdater(painter.Pass(),
-                                       stats_instrumentation,
-                                       layer_id));
+      new SkPictureContentLayerUpdater(painter.Pass(), stats_instrumentation));
 }
 
 scoped_ptr<LayerUpdater::Resource> SkPictureContentLayerUpdater::CreateResource(
diff --git a/cc/resources/skpicture_content_layer_updater.h b/cc/resources/skpicture_content_layer_updater.h
index a835744..b1ac917 100644
--- a/cc/resources/skpicture_content_layer_updater.h
+++ b/cc/resources/skpicture_content_layer_updater.h
@@ -41,8 +41,7 @@ class SkPictureContentLayerUpdater : public ContentLayerUpdater {
 
   static scoped_refptr<SkPictureContentLayerUpdater> Create(
       scoped_ptr<LayerPainter> painter,
-      RenderingStatsInstrumentation* stats_instrumentation,
-      int layer_id);
+      RenderingStatsInstrumentation* stats_instrumentation);
 
   virtual scoped_ptr<LayerUpdater::Resource> CreateResource(
       PrioritizedResourceManager* manager) OVERRIDE;
@@ -51,8 +50,7 @@ class SkPictureContentLayerUpdater : public ContentLayerUpdater {
  protected:
   SkPictureContentLayerUpdater(
       scoped_ptr<LayerPainter> painter,
-      RenderingStatsInstrumentation* stats_instrumentation,
-      int layer_id);
+      RenderingStatsInstrumentation* stats_instrumentation);
   virtual ~SkPictureContentLayerUpdater();
 
   virtual void PrepareToUpdate(gfx::Rect content_rect,
diff --git a/cc/resources/tile_manager.cc b/cc/resources/tile_manager.cc
index 5c54b1e..902cf55 100644
--- a/cc/resources/tile_manager.cc
+++ b/cc/resources/tile_manager.cc
@@ -936,8 +936,7 @@ void TileManager::RunRasterTask(
   TRACE_EVENT1(
       "cc", "TileManager::RunRasterTask",
       "metadata", TracedValue::FromValue(metadata.AsValue().release()));
-  devtools_instrumentation::ScopedLayerTask raster_task(
-      devtools_instrumentation::kRasterTask, metadata.layer_id);
+  devtools_instrumentation::ScopedRasterTask raster_task(metadata.layer_id);
 
   DCHECK(picture_pile);
   DCHECK(analysis);
@@ -981,8 +980,7 @@ void TileManager::RunImageDecodeTask(
     int layer_id,
     RenderingStatsInstrumentation* stats_instrumentation) {
   TRACE_EVENT0("cc", "TileManager::RunImageDecodeTask");
-  devtools_instrumentation::ScopedLayerTask image_decode_task(
-      devtools_instrumentation::kImageDecodeTask, layer_id);
+  devtools_instrumentation::ScopedImageDecodeTask image_decode_task(layer_id);
   base::TimeTicks start_time = stats_instrumentation->StartRecording();
   pixel_ref->Decode();
   base::TimeDelta duration = stats_instrumentation->EndRecording(start_time);