Add UMA stats to track LCD text AA effort.

BUG=235480

Review URL: https://chromiumcodereview.appspot.com/14932016

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@202104 0039d316-1c4b-4281-b951-d872f2087c98

9 files changed, 114 insertions, 1 deletions

diff --git a/cc/layers/content_layer.cc b/cc/layers/content_layer.cc
index 44af47e..9269f7c 100644
--- a/cc/layers/content_layer.cc
+++ b/cc/layers/content_layer.cc
@@ -132,4 +132,8 @@ void ContentLayer::UpdateCanUseLCDText() {
     client_->DidChangeLayerCanUseLCDText();
 }
 
+bool ContentLayer::SupportsLCDText() const {
+  return true;
+}
+
 }  // namespace cc
diff --git a/cc/layers/content_layer.h b/cc/layers/content_layer.h
index 79394de..db574bc 100644
--- a/cc/layers/content_layer.h
+++ b/cc/layers/content_layer.h
@@ -50,6 +50,8 @@ class CC_EXPORT ContentLayer : public TiledLayer {
 
   virtual void SetContentsOpaque(bool contents_opaque) OVERRIDE;
 
+  virtual bool SupportsLCDText() const OVERRIDE;
+
  protected:
   explicit ContentLayer(ContentLayerClient* client);
   virtual ~ContentLayer();
diff --git a/cc/layers/layer.cc b/cc/layers/layer.cc
index cdc2d8d..0390f04 100644
--- a/cc/layers/layer.cc
+++ b/cc/layers/layer.cc
@@ -852,4 +852,8 @@ RenderingStatsInstrumentation* Layer::rendering_stats_instrumentation() const {
   return layer_tree_host_->rendering_stats_instrumentation();
 }
 
+bool Layer::SupportsLCDText() const {
+  return false;
+}
+
 }  // namespace cc
diff --git a/cc/layers/layer.h b/cc/layers/layer.h
index 1c1f3e4..ee8cd02 100644
--- a/cc/layers/layer.h
+++ b/cc/layers/layer.h
@@ -372,6 +372,8 @@ class CC_EXPORT Layer : public base::RefCounted<Layer>,
   float raster_scale() const { return raster_scale_; }
   bool raster_scale_is_unknown() const { return raster_scale_ == 0.f; }
 
+  virtual bool SupportsLCDText() const;
+
  protected:
   friend class LayerImpl;
   friend class TreeSynchronizer;
diff --git a/cc/layers/picture_layer.cc b/cc/layers/picture_layer.cc
index 4f4b385..e01656a 100644
--- a/cc/layers/picture_layer.cc
+++ b/cc/layers/picture_layer.cc
@@ -102,4 +102,8 @@ void PictureLayer::SetIsMask(bool is_mask) {
   is_mask_ = is_mask;
 }
 
+bool PictureLayer::SupportsLCDText() const {
+  return true;
+}
+
 }  // namespace cc
diff --git a/cc/layers/picture_layer.h b/cc/layers/picture_layer.h
index 0cb1583..bb5892a 100644
--- a/cc/layers/picture_layer.h
+++ b/cc/layers/picture_layer.h
@@ -35,6 +35,7 @@ class CC_EXPORT PictureLayer : public ContentsScalingLayer {
       const OcclusionTracker* occlusion,
       RenderingStats* stats) OVERRIDE;
   virtual void SetIsMask(bool is_mask) OVERRIDE;
+  virtual bool SupportsLCDText() const OVERRIDE;
 
  protected:
   explicit PictureLayer(ContentLayerClient* client);
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index 4448f87..b8b02be 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -11,6 +11,7 @@
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/stl_util.h"
 #include "base/string_number_conversions.h"
 #include "cc/animation/animation_registrar.h"
@@ -97,7 +98,8 @@ LayerTreeHost::LayerTreeHost(LayerTreeHostClient* client,
       background_color_(SK_ColorWHITE),
       has_transparent_background_(false),
       partial_texture_update_requests_(0),
-      in_paint_layer_contents_(false) {
+      in_paint_layer_contents_(false),
+      total_frames_used_for_lcd_text_metrics_(0) {
   if (settings_.accelerated_animation_enabled)
     animation_registrar_ = AnimationRegistrar::Create();
   s_num_layer_tree_instances++;
@@ -672,6 +674,42 @@ static Layer* FindFirstScrollableLayer(Layer* layer) {
   return NULL;
 }
 
+class CalculateLCDTextMetricsFunctor {
+ public:
+  void operator()(Layer* layer) {
+    LayerTreeHost* layer_tree_host = layer->layer_tree_host();
+    if (!layer_tree_host)
+      return;
+
+    if (!layer->SupportsLCDText())
+      return;
+
+    bool update_total_num_cc_layers_can_use_lcd_text = false;
+    bool update_total_num_cc_layers_will_use_lcd_text = false;
+    if (layer->draw_properties().can_use_lcd_text) {
+      update_total_num_cc_layers_can_use_lcd_text = true;
+      if (layer->contents_opaque())
+        update_total_num_cc_layers_will_use_lcd_text = true;
+    }
+
+    layer_tree_host->IncrementLCDTextMetrics(
+        update_total_num_cc_layers_can_use_lcd_text,
+        update_total_num_cc_layers_will_use_lcd_text);
+  }
+};
+
+void LayerTreeHost::IncrementLCDTextMetrics(
+    bool update_total_num_cc_layers_can_use_lcd_text,
+    bool update_total_num_cc_layers_will_use_lcd_text) {
+  lcd_text_metrics_.total_num_cc_layers++;
+  if (update_total_num_cc_layers_can_use_lcd_text)
+    lcd_text_metrics_.total_num_cc_layers_can_use_lcd_text++;
+  if (update_total_num_cc_layers_will_use_lcd_text) {
+    DCHECK(update_total_num_cc_layers_can_use_lcd_text);
+    lcd_text_metrics_.total_num_cc_layers_will_use_lcd_text++;
+  }
+}
+
 void LayerTreeHost::UpdateLayers(Layer* root_layer,
                                  ResourceUpdateQueue* queue) {
   TRACE_EVENT1("cc", "LayerTreeHost::UpdateLayers",
@@ -694,6 +732,27 @@ void LayerTreeHost::UpdateLayers(Layer* root_layer,
         settings_.can_use_lcd_text,
         settings_.layer_transforms_should_scale_layer_contents,
         &update_list);
+
+    if (total_frames_used_for_lcd_text_metrics_ <=
+        kTotalFramesToUseForLCDTextMetrics) {
+      LayerTreeHostCommon::CallFunctionForSubtree<
+          CalculateLCDTextMetricsFunctor, Layer>(root_layer);
+      total_frames_used_for_lcd_text_metrics_++;
+    }
+
+    if (total_frames_used_for_lcd_text_metrics_ ==
+        kTotalFramesToUseForLCDTextMetrics) {
+      total_frames_used_for_lcd_text_metrics_++;
+
+      UMA_HISTOGRAM_PERCENTAGE(
+          "Renderer4.LCDText.PercentageOfCandidateLayers",
+          lcd_text_metrics_.total_num_cc_layers_can_use_lcd_text * 100.0 /
+          lcd_text_metrics_.total_num_cc_layers);
+      UMA_HISTOGRAM_PERCENTAGE(
+          "Renderer4.LCDText.PercentageOfAALayers",
+          lcd_text_metrics_.total_num_cc_layers_will_use_lcd_text * 100.0 /
+          lcd_text_metrics_.total_num_cc_layers_can_use_lcd_text);
+    }
   }
 
   // Reset partial texture update requests.
diff --git a/cc/trees/layer_tree_host.h b/cc/trees/layer_tree_host.h
index ea2997a..d0f6801 100644
--- a/cc/trees/layer_tree_host.h
+++ b/cc/trees/layer_tree_host.h
@@ -255,6 +255,10 @@ class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
 
   bool in_paint_layer_contents() const { return in_paint_layer_contents_; }
 
+  void IncrementLCDTextMetrics(
+      bool update_total_num_cc_layers_can_use_lcd_text,
+      bool update_total_num_cc_layers_will_use_lcd_text);
+
  protected:
   LayerTreeHost(LayerTreeHostClient* client, const LayerTreeSettings& settings);
   bool Initialize(scoped_ptr<Thread> impl_thread);
@@ -346,6 +350,21 @@ class CC_EXPORT LayerTreeHost : NON_EXPORTED_BASE(public RateLimiterClient) {
 
   LatencyInfo latency_info_;
 
+  static const int kTotalFramesToUseForLCDTextMetrics = 50;
+  int total_frames_used_for_lcd_text_metrics_;
+
+  struct LCDTextMetrics {
+    LCDTextMetrics()
+        : total_num_cc_layers(0),
+          total_num_cc_layers_can_use_lcd_text(0),
+          total_num_cc_layers_will_use_lcd_text(0) {}
+
+    int64 total_num_cc_layers;
+    int64 total_num_cc_layers_can_use_lcd_text;
+    int64 total_num_cc_layers_will_use_lcd_text;
+  };
+  LCDTextMetrics lcd_text_metrics_;
+
   DISALLOW_COPY_AND_ASSIGN(LayerTreeHost);
 };
 
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index bd799a0..5510996 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -7220,6 +7220,24 @@ other types of suffix sets.
   <summary>TBD</summary>
 </histogram>
 
+<histogram name="Renderer4.LCDText.PercentageOfAALayers" units="%">
+  <summary>
+    The ratio of LCDText CC Layers / candidate LCDText layers. Recorded in
+    LayerTreeHost, after LayerTreeHostCommon::CalculateDrawProperties() has
+    computed the properties we need. Only recorded for the first 50 frames of
+    every page.
+  </summary>
+</histogram>
+
+<histogram name="Renderer4.LCDText.PercentageOfCandidateLayers" units="%">
+  <summary>
+    The ratio of CC Layers which are candidates for LCDText AA / total picture
+    or content Layers.  Recorded in LayerTreeHost, after
+    LayerTreeHostCommon::CalculateDrawProperties() has computed the properties
+    we need. Only recorded for the first 50 frames of every page.
+  </summary>
+</histogram>
+
 <histogram name="Renderer4.RequestToFinish" units="milliseconds">
   <summary>
     Time from &quot;request&quot; to &quot;finish.&quot;  &quot;Request&quot;==