hnakashima@chromium.org Tracks user actions in the PDF viewer. Logged when the document is opened and when one of the relevant user actions is taken, such as opening the bookmarks bar or setting the zoom mode to fit-to-page. The enum values that are named "First" are logged only once per document, so that we can measure in what percentage of documents a given action was performed at least once. nigi@chromium.org thestig@chromium.org Records encountering a PDF attachment with a specific file extension. This is logged when a document is opened in the PDF viewer but not in the Print Preview. The index of "directory" won't be used for this log since a PDF attachment cannot be a directory. The index of "unknown extension" won't be used for this log since it will be represented as the index of "other". dhoss@chromium.org kmoon@chromium.org thestig@chromium.org Tracks what types of forms are present in PDF document, logged when the document finishes loading. nigi@chromium.org thestig@chromium.org Measures if PDFs opened in the PDF viewer have attachments. This is logged whenever a document is opened in the PDF viewer. Removed 04/2022. It's no longer needed. thestig@chromium.org ankk@microsoft.com mohitb@microsoft.com virens@microsoft.com Records the number of overlapping link and highlight annotations in a PDF page. This is logged once per page whenever accessibility tree creation is triggered for that page. It will not be logged on render or scroll operations. kmoon@chromium.org thestig@chromium.org Tracks what happens when Chrome tries to load a PDF. This metric tracks all cases, but is focused on measuring failed PDF embeds, which occur if the user is on Android, or if PDF plugin is disabled. hnakashima@chromium.org thestig@chromium.org Tracks the number of pages in PDF documents opened in the PDF viewer. nigi@chromium.org thestig@chromium.org Time used for rendering and painting all the visible pages in the PDF viewer. dhoss@chromium.org thestig@chromium.org Tracks versions of documents opened in the PDF viewer.