[Paint Preview] Usage, Time and Frame Count UMA

This adds UMA metrics for
- Capture time in spent in Blink
- Total capture time
- Usage/Success counters
- Frame count to evaluate total frames captured

Follow-up CLs will be needed for UKMs and disk-usage.

Bug: 1038390
Change-Id: I1b7e0a844da23d23257cb75ad6673ff31a730955
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1986773Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Ian Vollick <vollick@chromium.org>
Commit-Queue: Calder Kitagawa <ckitagawa@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734644}

components/paint_preview/browser/paint_preview_base_service.cc

@@ -10,7 +10,7 @@
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/logging.h"
-#include "base/task/post_task.h"
+#include "base/metrics/histogram_functions.h"
 #include "build/build_config.h"
 #include "components/keyed_service/core/keyed_service.h"
 #include "components/paint_preview/browser/compositor_utils.h"
@@ -98,10 +98,12 @@ void PaintPreviewBaseService::CapturePaintPreview(
   params.is_main_frame = (render_frame_host == web_contents->GetMainFrame());
   params.root_dir = root_dir;
 
+  auto start_time = base::TimeTicks::Now();
   client->CapturePaintPreview(
       params, render_frame_host,
       base::BindOnce(&PaintPreviewBaseService::OnCaptured,
-                     weak_ptr_factory_.GetWeakPtr(), std::move(callback)));
+                     weak_ptr_factory_.GetWeakPtr(), start_time,
+                     std::move(callback)));
 }
 
 std::unique_ptr<PaintPreviewCompositorService>
@@ -112,6 +114,7 @@ PaintPreviewBaseService::StartCompositorService(
 }
 
 void PaintPreviewBaseService::OnCaptured(
+    base::TimeTicks start_time,
     OnCapturedCallback callback,
     base::UnguessableToken guid,
     mojom::PaintPreviewStatus status,
@@ -122,6 +125,8 @@ void PaintPreviewBaseService::OnCaptured(
     std::move(callback).Run(kCaptureFailed, nullptr);
     return;
   }
+  base::UmaHistogramTimes("Browser.PaintPreview.Capture.TotalCaptureDuration",
+                          base::TimeTicks::Now() - start_time);
   std::move(callback).Run(kOk, std::move(proto));
 }
 

components/paint_preview/browser/paint_preview_base_service.h

@@ -12,6 +12,7 @@
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/optional.h"
+#include "base/time/time.h"
 #include "base/unguessable_token.h"
 #include "build/build_config.h"
 #include "components/keyed_service/core/keyed_service.h"
@@ -119,7 +120,8 @@ class PaintPreviewBaseService : public KeyedService {
 #endif  // defined(OS_ANDROID)
 
  private:
-  void OnCaptured(OnCapturedCallback callback,
+  void OnCaptured(base::TimeTicks start_time,
+                  OnCapturedCallback callback,
                   base::UnguessableToken guid,
                   mojom::PaintPreviewStatus status,
                   std::unique_ptr<PaintPreviewProto> proto);

components/paint_preview/browser/paint_preview_client.cc

@@ -6,6 +6,7 @@
 
 #include <utility>
 
+#include "base/metrics/histogram_functions.h"
 #include "base/strings/strcat.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/task/post_task.h"
@@ -344,7 +345,14 @@ void PaintPreviewClient::OnFinished(base::UnguessableToken guid,
                                     PaintPreviewData* document_data) {
   if (!document_data)
     return;
+
+  base::UmaHistogramBoolean("Browser.PaintPreview.Capture.Success",
+                            document_data->proto != nullptr);
   if (document_data->proto) {
+    base::UmaHistogramCounts100(
+        "Browser.PaintPreview.Capture.NumberOfFramesCaptured",
+        document_data->finished_subframes.size());
+
     // At a minimum one frame was captured successfully, it is up to the
     // caller to decide if a partial success is acceptable based on what is
     // contained in the proto.

components/paint_preview/renderer/paint_preview_recorder_impl.cc

@@ -7,7 +7,9 @@
 #include <utility>
 
 #include "base/auto_reset.h"
+#include "base/metrics/histogram_functions.h"
 #include "base/task_runner.h"
+#include "base/time/time.h"
 #include "cc/paint/paint_record.h"
 #include "cc/paint/paint_recorder.h"
 #include "components/paint_preview/renderer/paint_preview_recorder_utils.h"
@@ -111,7 +113,35 @@ void PaintPreviewRecorderImpl::CapturePaintPreviewInternal(
   cc::PaintCanvas* canvas =
       recorder.beginRecording(bounds.width(), bounds.height());
   canvas->SetPaintPreviewTracker(&tracker);
+
+  // Use time ticks manually rather than a histogram macro so as to;
+  // 1. Account for main frames and subframes separately.
+  // 2. Mitigate binary size as this won't be used that often.
+  // 3. Record only on successes as failures are likely to be outliers (fast or
+  //    slow).
+  base::TimeTicks start_time = base::TimeTicks::Now();
   bool success = frame->CapturePaintPreview(bounds, canvas);
+  base::TimeDelta capture_time = base::TimeTicks::Now() - start_time;
+
+  if (is_main_frame_) {
+    base::UmaHistogramBoolean("Renderer.PaintPreview.Capture.MainFrameSuccess",
+                              success);
+    if (success) {
+      // Main frame should generally be the largest cost and will always run so
+      // it is tracked separately.
+      base::UmaHistogramTimes(
+          "Renderer.PaintPreview.Capture.MainFrameBlinkCaptureDuration",
+          capture_time);
+    }
+  } else {
+    base::UmaHistogramBoolean("Renderer.PaintPreview.Capture.SubframeSuccess",
+                              success);
+    if (success) {
+      base::UmaHistogramTimes(
+          "Renderer.PaintPreview.Capture.SubframeBlinkCaptureDuration",
+          capture_time);
+    }
+  }
 
   // Restore to before out-of-lifecycle paint phase.
   frame->DispatchAfterPrintEvent();

tools/metrics/histograms/histograms.xml

@@ -20176,6 +20176,37 @@ uploading your change for review.
   </summary>
 </histogram>
 
+<histogram name="Browser.PaintPreview.Capture.NumberOfFramesCaptured"
+    units="units" expires_after="2020-06-01">
+  <owner>ckitagawa@chromium.org</owner>
+  <owner>mahmoudi@chromium.org</owner>
+  <owner>vollick@chromium.org</owner>
+  <summary>
+    Records the number of frames captured by a paint preview if it succeeded.
+  </summary>
+</histogram>
+
+<histogram name="Browser.PaintPreview.Capture.Success" units="units"
+    expires_after="2020-06-01">
+  <owner>ckitagawa@chromium.org</owner>
+  <owner>mahmoudi@chromium.org</owner>
+  <owner>vollick@chromium.org</owner>
+  <summary>
+    Records a boolean indicating whether a capture attempt was successful.
+  </summary>
+</histogram>
+
+<histogram name="Browser.PaintPreview.Capture.TotalCaptureDuration" units="ms"
+    expires_after="2020-06-01">
+  <owner>ckitagawa@chromium.org</owner>
+  <owner>mahmoudi@chromium.org</owner>
+  <owner>vollick@chromium.org</owner>
+  <summary>
+    Records the total time spent capturing a paint preview of a page. This
+    includes capture and serialization of all frames and IPC time.
+  </summary>
+</histogram>
+
 <histogram name="Browser.Responsiveness.JankyIntervalsPerThirtySeconds"
     units="janks" expires_after="never">
 <!-- expires-never: guiding metric (internal: go/chrome-browser-guiding-metrics) -->
@@ -124742,6 +124773,48 @@ uploading your change for review.
   </summary>
 </histogram>
 
+<histogram name="Renderer.PaintPreview.Capture.MainFrameBlinkCaptureDuration"
+    units="ms" expires_after="2020-06-01">
+  <owner>ckitagawa@chromium.org</owner>
+  <owner>mahmoudi@chromium.org</owner>
+  <owner>vollick@chromium.org</owner>
+  <summary>
+    Records the number of milliseconds spent blocking Blink's main thread while
+    capturing the main frame.
+  </summary>
+</histogram>
+
+<histogram name="Renderer.PaintPreview.Capture.MainFrameSuccess" units="units"
+    expires_after="2020-06-01">
+  <owner>ckitagawa@chromium.org</owner>
+  <owner>mahmoudi@chromium.org</owner>
+  <owner>vollick@chromium.org</owner>
+  <summary>
+    Records a boolean indicating whether a capture for the main frame succeeded.
+  </summary>
+</histogram>
+
+<histogram name="Renderer.PaintPreview.Capture.SubframeBlinkCaptureDuration"
+    units="ms" expires_after="2020-06-01">
+  <owner>ckitagawa@chromium.org</owner>
+  <owner>mahmoudi@chromium.org</owner>
+  <owner>vollick@chromium.org</owner>
+  <summary>
+    Records the number of milliseconds spent blocking Blink's main thread while
+    capturing a subframe.
+  </summary>
+</histogram>
+
+<histogram name="Renderer.PaintPreview.Capture.SubframeSuccess" units="units"
+    expires_after="2020-06-01">
+  <owner>ckitagawa@chromium.org</owner>
+  <owner>mahmoudi@chromium.org</owner>
+  <owner>vollick@chromium.org</owner>
+  <summary>
+    Records a boolean indicating whether a capture for a subframe succeeded.
+  </summary>
+</histogram>
+
 <histogram name="Renderer.PixelIncreaseFromTransitions" units="units"
     expires_after="2016-04-29">
   <obsolete>