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 bc46ae630f07dc43b5a2ede866f028b3360112c5..aa64b71baa35bb63240de7bc97efbfdc467fe113 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -3579,6 +3579,35 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>Time spent on 2D canvas putImageData API call.</summary>
 </histogram>
 
+<histogram name="Blink.Canvas.ToBlob.IdleEncodeDuration" units="microseconds">
+  <owner>junov@chromium.org</owner>
+  <owner>xlai@chromium.org</owner>

[Ilya Sherman, 2016/06/29 22:01:02]

Out of curiousity, why are you not listing yourself as an owner of the
histograms that you're adding?

[xidachen, 2016/06/30 01:53:38]

xlai@ implements the toBlob function and junov@ is our TL. I believe that xlai@
will be closely monitoring this histogram in the future.

+  <summary>Time spent on idle encoding.</summary>

[Ilya Sherman, 2016/06/29 22:01:03]

What is "idle encoding"?  In general, for events that measure a duration, it's
best to be fairly precise about the start and end events, since they're not
always obvious to someone just viewing the dashboard.

[xidachen, 2016/06/30 01:53:38]

Done.

+</histogram>
+
+<histogram name="Blink.Canvas.ToBlob.IdleTaskStatus" enum="IdleTaskStatus">
+  <owner>junov@chromium.org</owner>
+  <owner>xlai@chromium.org</owner>
+  <summary>
+    Records the status of the idle tasks when finishing a toBlob call.

[Ilya Sherman, 2016/06/29 22:01:03]

nit: s/tasks/task ?

[xidachen, 2016/06/30 01:53:38]

Done.

+  </summary>
+</histogram>
+
+<histogram name="Blink.Canvas.ToBlob.InitiateEncodingDelay"
+    units="microseconds">
+  <owner>junov@chromium.org</owner>
+  <owner>xlai@chromium.org</owner>
+  <summary>
+    Time elapsed from schedule initiate encoding to start initiate encoding.

[Ilya Sherman, 2016/06/29 22:01:03]

nit: s/schedule/scheduling and s/start/starting.  Also, what does "initiate
encoding" mean, exactly?  Would it be semantically valid to simply drop both
uses of "initiate" in this sentence?

[xidachen, 2016/06/30 01:53:38]

Done.

+  </summary>
+</histogram>
+
+<histogram name="Blink.Canvas.ToBlobDuration" units="microseconds">
+  <owner>junov@chromium.org</owner>
+  <owner>xlai@chromium.org</owner>
+  <summary>Time spent on 2D canvas toBlob API call.</summary>
+</histogram>
+
 <histogram name="Blink.Canvas.ToDataURL" units="microseconds">
   <owner>junov@chromium.org</owner>
   <summary>Time spent on 2D canvas toDataURL API call.</summary>
@@ -78461,6 +78490,16 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </int>
 </enum>
 
+<enum name="IdleTaskStatus" type="int">
+  <int value="0" label="IdleTaskNotStarted"/>

[Ilya Sherman, 2016/06/29 22:01:03]

nit: These enum labels are fine if you want them to match the C++ code, but I'd
personally recommend more readable names like "Not started", etc.

+  <int value="1" label="IdleTaskStarted"/>
+  <int value="2" label="IdleTaskCompleted"/>
+  <int value="3" label="IdleTaskFailed"/>
+  <int value="4" label="IdleTaskSwitchedToMainThreadTask"/>
+  <int value="5" label="IdleTaskNotSupported"/>
+  <int value="6" label="IdleTaskNotUsed"/>

[Ilya Sherman, 2016/06/29 22:01:02]

nit: No need to list the unused overflow bucket in histograms.xml

[xidachen, 2016/06/30 01:53:38]

Done.

+</enum>
+
 <enum name="IMECommitType" type="int">
   <obsolete>
     Deprecated 03/2015, and replaced by IMECommitType2.
@@ -93571,6 +93610,26 @@ To add a new entry, add it with any value and run test to compute valid value.
   <affected-histogram name="Blink.Canvas.PutImageData"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="BlinkCanvasToBlobIdleEncodeType" separator=".">
+  <suffix name="JPEG"/>
+  <suffix name="PNG"/>
+  <affected-histogram name="Blink.Canvas.ToBlob.IdleEncodeDuration"/>
+</histogram_suffixes>
+
+<histogram_suffixes name="BlinkCanvasToBlobInitiateEncodingDelayType"
+    separator=".">
+  <suffix name="JPEG"/>
+  <suffix name="PNG"/>
+  <affected-histogram name="Blink.Canvas.ToBlob.InitiateEncodingDelay"/>
+</histogram_suffixes>

[Ilya Sherman, 2016/06/29 22:01:03]

Could the above two histogram_suffixes elements be merged?  They share the same
suffixes, and seem likely to continue to do so if more suffixes are ever added.

[xidachen, 2016/06/30 01:53:38]

Done.

+
+<histogram_suffixes name="BlinkCanvasToBlobType" separator=".">
+  <suffix name="JPEG"/>
+  <suffix name="PNG"/>
+  <suffix name="WEBP"/>
+  <affected-histogram name="Blink.Canvas.ToBlobDuration"/>
+</histogram_suffixes>
+
 <histogram_suffixes name="BlinkCanvasToDataURLTime" separator=".">
   <suffix name="BMP"/>
   <suffix name="GIF"/>