Add timer to OffscreenCanvas's commit API

third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp

Index: third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp b/third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp
index a40cfba6a760d212cfec49a7c99957de551565fc..5b7e445fc9909de13ab1c02d4c9b262fac6776ac 100644
--- a/third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp
+++ b/third_party/WebKit/Source/platform/graphics/OffscreenCanvasFrameDispatcherImpl.cpp
@@ -152,6 +152,7 @@ void OffscreenCanvasFrameDispatcherImpl::
 
 void OffscreenCanvasFrameDispatcherImpl::dispatchFrame(
     RefPtr<StaticBitmapImage> image,
+    double commitStartTime,
     bool isWebGLSoftwareRendering /* This flag is true when WebGL's commit is
     called on SwiftShader. */) {
   if (!image)
@@ -182,6 +183,7 @@ void OffscreenCanvasFrameDispatcherImpl::dispatchFrame(
   // TODO(crbug.com/646022): making this overlay-able.
   resource.is_overlay_candidate = false;
 
+  OffscreenCanvasCommitType commitType;
   DEFINE_THREAD_SAFE_STATIC_LOCAL(
       EnumerationHistogram, commitTypeHistogram,
       new EnumerationHistogram("OffscreenCanvas.CommitType",
@@ -190,28 +192,29 @@ void OffscreenCanvasFrameDispatcherImpl::dispatchFrame(
     if (Platform::current()->isGPUCompositingEnabled() &&
         !isWebGLSoftwareRendering) {
       // Case 1: both canvas and compositor are gpu accelerated.
-      commitTypeHistogram.count(CommitGPUCanvasGPUCompositing);
+      commitType = CommitGPUCanvasGPUCompositing;
       setTransferableResourceToStaticBitmapImage(resource, image);
     } else {
       // Case 2: canvas is accelerated but --disable-gpu-compositing is
       // specified, or WebGL's commit is called with SwiftShader. The latter
       // case is indicated by
       // WebGraphicsContext3DProvider::isSoftwareRendering.
-      commitTypeHistogram.count(CommitGPUCanvasSoftwareCompositing);
+      commitType = CommitGPUCanvasSoftwareCompositing;
       setTransferableResourceToSharedBitmap(resource, image);
     }
   } else {
     if (Platform::current()->isGPUCompositingEnabled() &&
         !isWebGLSoftwareRendering) {
       // Case 3: canvas is not gpu-accelerated, but compositor is
-      commitTypeHistogram.count(CommitSoftwareCanvasGPUCompositing);
+      commitType = CommitSoftwareCanvasGPUCompositing;
       setTransferableResourceToSharedGPUContext(resource, image);
     } else {
       // Case 4: both canvas and compositor are not gpu accelerated.
-      commitTypeHistogram.count(CommitSoftwareCanvasSoftwareCompositing);
+      commitType = CommitSoftwareCanvasSoftwareCompositing;
       setTransferableResourceToSharedBitmap(resource, image);
     }
   }
+  commitTypeHistogram.count(commitType);
 
   m_nextResourceId++;
   frame.delegated_frame_data->resource_list.push_back(std::move(resource));
@@ -238,6 +241,33 @@ void OffscreenCanvasFrameDispatcherImpl::dispatchFrame(
 
   frame.delegated_frame_data->render_pass_list.push_back(std::move(pass));
 
+  double elapsedTime = WTF::monotonicallyIncreasingTime() - commitStartTime;
+  if (commitType == CommitGPUCanvasGPUCompositing) {

[Justin Novosad, 2016/10/12 21:11:12]

Nit: Should use switch/case IMHO

[xidachen, 2016/10/13 01:39:24]

Done.

+    DEFINE_STATIC_LOCAL(CustomCountHistogram,
+                        commitGPUCanvasGPUCompositingTimer,
+                        ("Blink.Canvas.OffscreenCommit.GPUCanvasGPUCompositing",
+                         0, 10000000, 50));

[Justin Novosad, 2016/10/12 21:11:12]

I think we should double the number of categories to track calls made on the
main thread separately from those made in workers.  Ther might not be much
difference between the two today, but there could be when we address
crbug.com/655278

[xidachen, 2016/10/13 01:39:24]

Done.

+    commitGPUCanvasGPUCompositingTimer.count(elapsedTime * 1000000.0);
+  } else if (commitType == CommitGPUCanvasSoftwareCompositing) {
+    DEFINE_STATIC_LOCAL(
+        CustomCountHistogram, commitGPUCanvasSoftwareCompositingTimer,
+        ("Blink.Canvas.OffscreenCommit.GPUCanvasSoftwareCompositing", 0,
+         10000000, 50));
+    commitGPUCanvasSoftwareCompositingTimer.count(elapsedTime * 1000000.0);
+  } else if (commitType == CommitSoftwareCanvasGPUCompositing) {
+    DEFINE_STATIC_LOCAL(
+        CustomCountHistogram, commitSoftwareCanvasGPUCompositingTimer,
+        ("Blink.Canvas.OffscreenCommit.SoftwareCanvasGPUCompositing", 0,
+         10000000, 50));
+    commitSoftwareCanvasGPUCompositingTimer.count(elapsedTime * 1000000.0);
+  } else {
+    DEFINE_STATIC_LOCAL(
+        CustomCountHistogram, commitSoftwareCanvasSoftwareCompositingTimer,
+        ("Blink.Canvas.OffscreenCommit.SoftwareCanvasSoftwareCompositing", 0,
+         10000000, 50));
+    commitSoftwareCanvasSoftwareCompositingTimer.count(elapsedTime * 1000000.0);
+  }
+
   m_sink->SubmitCompositorFrame(std::move(frame), base::Closure());
 }