Add metrics for offscreen canvas

Bug: 894043
Change-Id: Idcfd3f4d430c7bce4c13448c80996128ca831f72
Reviewed-on: https://chromium-review.googlesource.com/c/1265815
Commit-Queue: Aaron Krajeski <aaronhk@chromium.org>
Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Reviewed-by: Robert Kaplow (sloooow) <rkaplow@chromium.org>
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599659}

third_party/blink/renderer/bindings/core/v8/serialization/serialized_script_value.cc

@@ -369,6 +369,7 @@ void SerializedScriptValue::TransferOffscreenCanvas(
     }
     visited.insert(offscreen_canvases[i].Get());
     offscreen_canvases[i].Get()->SetNeutered();
+    offscreen_canvases[i].Get()->RecordTransfer();
   }
 }
 

third_party/blink/renderer/core/html/canvas/canvas_rendering_context.h

@@ -75,6 +75,7 @@ class CORE_EXPORT CanvasRenderingContext : public ScriptWrappable,
     kContextXRPresent = 6,
     kContextWebgl2Compute = 7,
     kContextTypeCount,
+    kMaxValue = kContextWebgl2Compute,
   };
 
   static ContextType ContextTypeFromId(const String& id);

third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.cc

@@ -27,6 +27,7 @@
 #include "third_party/blink/renderer/platform/graphics/image.h"
 #include "third_party/blink/renderer/platform/graphics/skia/skia_utils.h"
 #include "third_party/blink/renderer/platform/graphics/static_bitmap_image.h"
+#include "third_party/blink/renderer/platform/histogram.h"
 #include "third_party/blink/renderer/platform/image-encoders/image_encoder_utils.h"
 #include "third_party/blink/renderer/platform/instrumentation/tracing/trace_event.h"
 #include "third_party/blink/renderer/platform/wtf/math_extras.h"
@@ -36,7 +37,14 @@ namespace blink {
 
 OffscreenCanvas::OffscreenCanvas(const IntSize& size) : size_(size) {}
 
+void OffscreenCanvas::RecordCanvasSizeToUMA(unsigned width, unsigned height) {
+  UMA_HISTOGRAM_CUSTOM_COUNTS("Blink.OffscreenCanvas.SqrtNumberOfPixels",
+                              std::sqrt(width * height), 0, 5000, 100);
+}
+
 OffscreenCanvas* OffscreenCanvas::Create(unsigned width, unsigned height) {
+  UMA_HISTOGRAM_BOOLEAN("Blink.OffscreenCanvas.NewOffscreenCanvas", true);
+  RecordCanvasSizeToUMA(width, height);
   return new OffscreenCanvas(
       IntSize(clampTo<int>(width), clampTo<int>(height)));
 }
@@ -107,6 +115,9 @@ void OffscreenCanvas::SetSize(const IntSize& size) {
       origin_clean_ = true;
     }
   }
+  if (size != size_) {
+    RecordCanvasSizeToUMA(size.Width(), size.Height());
+  }
   size_ = size;
   if (frame_dispatcher_)
     frame_dispatcher_->Reshape(size_);
@@ -116,6 +127,10 @@ void OffscreenCanvas::SetSize(const IntSize& size) {
     context_->DidDraw();
 }
 
+void OffscreenCanvas::RecordTransfer() {
+  UMA_HISTOGRAM_BOOLEAN("Blink.OffscreenCanvas.Transferred", true);
+}
+
 void OffscreenCanvas::SetNeutered() {
   DCHECK(!context_);
   is_neutered_ = true;
@@ -203,6 +218,12 @@ CanvasRenderingContext* OffscreenCanvas::GetCanvasRenderingContext(
     return nullptr;
   }
 
+  // Log the aliased context type used.
+  if (!context_) {
+    UMA_HISTOGRAM_ENUMERATION("Blink.OffscreenCanvas.ContextType",
+                              context_type);
+  }
+
   CanvasRenderingContextFactory* factory =
       GetRenderingContextFactory(context_type);
   if (!factory)

third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.h

@@ -45,6 +45,9 @@ class CORE_EXPORT OffscreenCanvas final
   USING_GARBAGE_COLLECTED_MIXIN(OffscreenCanvas);
   USING_PRE_FINALIZER(OffscreenCanvas, Dispose);
 
+ private:
+  void static RecordCanvasSizeToUMA(unsigned width, unsigned height);
+
  public:
   static OffscreenCanvas* Create(unsigned width, unsigned height);
   ~OffscreenCanvas() override;
@@ -65,6 +68,7 @@ class CORE_EXPORT OffscreenCanvas final
 
   const IntSize& Size() const override { return size_; }
   void SetSize(const IntSize&);
+  void RecordTransfer();
 
   void SetPlaceholderCanvasId(DOMNodeId canvas_id);
   DOMNodeId PlaceholderCanvasId() const { return placeholder_canvas_id_; }

third_party/blink/renderer/modules/canvas/htmlcanvas/html_canvas_element_module.cc

@@ -9,6 +9,7 @@
 #include "third_party/blink/renderer/core/offscreencanvas/offscreen_canvas.h"
 #include "third_party/blink/renderer/modules/canvas/htmlcanvas/canvas_context_creation_attributes_helpers.h"
 #include "third_party/blink/renderer/modules/canvas/htmlcanvas/canvas_context_creation_attributes_module.h"
+#include "third_party/blink/renderer/platform/histogram.h"
 
 namespace blink {
 
@@ -38,16 +39,20 @@ void HTMLCanvasElementModule::getContext(
 OffscreenCanvas* HTMLCanvasElementModule::transferControlToOffscreen(
     HTMLCanvasElement& canvas,
     ExceptionState& exception_state) {
+  OffscreenCanvas* offscreen_canvas = nullptr;
   if (canvas.SurfaceLayerBridge()) {
     exception_state.ThrowDOMException(
         DOMExceptionCode::kInvalidStateError,
         "Cannot transfer control from a canvas for more than one time.");
-    return nullptr;
+  } else {
+    canvas.CreateLayer();
+    offscreen_canvas =
+        TransferControlToOffscreenInternal(canvas, exception_state);
   }
 
-  canvas.CreateLayer();
-
-  return TransferControlToOffscreenInternal(canvas, exception_state);
+  UMA_HISTOGRAM_BOOLEAN("Blink.OffscreenCanvas.TransferControlToOffscreen",
+                        bool(offscreen_canvas));
+  return offscreen_canvas;
 }
 
 OffscreenCanvas* HTMLCanvasElementModule::TransferControlToOffscreenInternal(

tools/metrics/histograms/histograms.xml

@@ -9436,6 +9436,51 @@ uploading your change for review.
   </summary>
 </histogram>
 
+<histogram name="Blink.OffscreenCanvas.ContextType" enum="CanvasContextType">
+  <owner>aaronhk@chromium.org</owner>
+  <owner>fserb@chromium.org</owner>
+  <summary>
+    Records the context type names used to create offscreen canvas rendering
+    contexts. Recorded in OffscreenCanvas::GetCanvasRenderingContext
+  </summary>
+</histogram>
+
+<histogram name="Blink.OffscreenCanvas.NewOffscreenCanvas" enum="Boolean">
+  <owner>aaronhk@chromium.org</owner>
+  <owner>fserb@chromium.org</owner>
+  <summary>
+    Records the creation of a new offscreen canvas in OffscreenCanvas::Create.
+  </summary>
+</histogram>
+
+<histogram name="Blink.OffscreenCanvas.SqrtNumberOfPixels" units="sqrt(pixels)">
+  <owner>aaronhk@chromium.org</owner>
+  <owner>fserb@chromium.org</owner>
+  <summary>
+    Stores the square root of the number of pixels in a new or resized offscreen
+    canvas.
+  </summary>
+</histogram>
+
+<histogram name="Blink.OffscreenCanvas.TransferControlToOffscreen"
+    enum="Boolean">
+  <owner>aaronhk@chromium.org</owner>
+  <owner>fserb@chromium.org</owner>
+  <summary>
+    Records a call to transfer a canvas offscreen. True indicates a successful
+    transfer, false for a failure.
+  </summary>
+</histogram>
+
+<histogram name="Blink.OffscreenCanvas.Transferred" enum="Boolean">
+  <owner>aaronhk@chromium.org</owner>
+  <owner>fserb@chromium.org</owner>
+  <summary>
+    Records when an offscreen canvas has been transferred from the main thread
+    to a worker.
+  </summary>
+</histogram>
+
 <histogram name="Blink.Paint.UpdateTime" units="microseconds">
   <owner>paint-dev@chromium.org</owner>
   <summary>