cc: Add UMA stats for record and raster time.

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index afcf18902794abf5d83b06866aca8ef1c8c8b269..5547bf3cde41a5f4c8671ef49e16af4b610c144b 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -31218,6 +31218,21 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Renderer4.PictureLayerUpdatePixelsPerMs">
+  <owner>paint-dev@chromium.org</owner>
+  <summary>
+    Area of recorded content, in pixels, divided by picture layer update time,
+    in milliseconds.
+  </summary>
+</histogram>
+
+<histogram name="Renderer4.PictureLayerUpdateUs" units="microseconds">
+  <owner>paint-dev@chromium.org</owner>
+  <summary>
+    Time spent updating (i.e. recording) a picture layer, in microseconds.
+  </summary>
+</histogram>
+
 <histogram name="Renderer4.pixelCountCulled_Draw" units="NormalizedPixels">
   <owner>wiltzius@chromium.org</owner>
   <summary>
@@ -31253,6 +31268,21 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   </summary>
 </histogram>
 
+<histogram name="Renderer4.RasterTaskPixelsPerMs">
+  <owner>paint-dev@chromium.org</owner>
+  <summary>
+    Rasterized area, in pixels, divided by rasterization time, in milliseconds,
+    of a compositor rasterization task.
+  </summary>
+</histogram>
+
+<histogram name="Renderer4.RasterTaskUs" units="microseconds">
+  <owner>paint-dev@chromium.org</owner>
+  <summary>
+    Time spent completing a compositor rasterization task, in microseconds.
+  </summary>
+</histogram>
+
 <histogram name="Renderer4.renderPassCount">
   <owner>wiltzius@chromium.org</owner>
   <summary>