Are you talking about the PDF.Actions.* metrics from r523164?

If yes, then there is PDFMetricsImpl for the regular PDF viewer and PDFMetricsDummy for print preview.

Lei or Henrique, do you know if the metrics we collect in OutOfProcessInstance::DocumentLoadComplete include the print PDFs?

Specific metrics:
PDF.PageCount
PDF.HasAttachment
PDF.IsLinearized
PDF.IsTagged
PDF.FormType

Yes, they should. See OutOfProcessInstance::DocumentLoadComplete(). It has a branch to do special things in print preview, but metrics logging is outside.

Marking this fixed, since it sounds like all of the metrics that we were concerned about are already being properly filtered for being non-print PDFs.

Sorry, I was not clear. I mean they are logged for both print preview and the pdf viewer. Do we want to change that?

Actually the print previews are not included in logs. Even though that code does run, the helper methods called for logging (HistogramCustomCounts, HistogramEnumeration) do not do anything if it's print preview.

Therefore, our numbers are right, they are just for the actual PDF viewer. Also verified this empirically looking at chrome://histograms.