Add a histogram to track the type of documents printed (HTML vs PDF)

chrome/browser/ui/webui/print_preview/print_preview_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/print_preview/print_preview_handler.h"
 
 #include <ctype.h>
 #include <stddef.h>
 
 #include <map>
@@ skipping 89 matching lines @@
 #include "chrome/browser/printing/cloud_print/privet_constants.h"
 #endif
 
 using content::BrowserThread;
 using content::RenderFrameHost;
 using content::WebContents;
 using printing::PrintViewManager;
 
 namespace {
 
+// This enum is used to back an UMA histogram, and should therefore be treated
+// as append only.
 enum UserActionBuckets {
   PRINT_TO_PRINTER,
   PRINT_TO_PDF,
   CANCEL,
   FALLBACK_TO_ADVANCED_SETTINGS_DIALOG,
   PREVIEW_FAILED,
   PREVIEW_STARTED,
   INITIATOR_CRASHED_UNUSED,
   INITIATOR_CLOSED,
   PRINT_WITH_CLOUD_PRINT,
   PRINT_WITH_PRIVET,
   PRINT_WITH_EXTENSION,
   USERACTION_BUCKET_BOUNDARY
 };
 
+// This enum is used to back an UMA histogram, and should therefore be treated
+// as append only.
 enum PrintSettingsBuckets {
   LANDSCAPE = 0,
   PORTRAIT,
   COLOR,
   BLACK_AND_WHITE,
   COLLATE,
   SIMPLEX,
   DUPLEX,
   TOTAL,
   HEADERS_AND_FOOTERS,
   CSS_BACKGROUND,
   SELECTION_ONLY,
   EXTERNAL_PDF_PREVIEW,
   PAGE_RANGE,
   DEFAULT_MEDIA,
   NON_DEFAULT_MEDIA,
   COPIES,
   NON_DEFAULT_MARGINS,
   DISTILL_PAGE_UNUSED,
   SCALING,
   PRINT_SETTINGS_BUCKET_BOUNDARY
 };
 
+// This enum is used to back an UMA histogram, and should therefore be treated
+// as append only.
+enum PrintDocumentTypeBuckets {
+  HTML_DOCUMENT = 0,

[Lei Zhang, 2017/02/25 01:04:01]

Maybe we should see how often users print images too? i.e. load
http://domain/foo.jpeg and print that directly.

+  PDF_DOCUMENT,
+  PRINT_DOCUMENT_TYPE_BUCKET_BOUNDARY
+};
+
 void ReportUserActionHistogram(enum UserActionBuckets event) {
   UMA_HISTOGRAM_ENUMERATION("PrintPreview.UserAction", event,
                             USERACTION_BUCKET_BOUNDARY);
 }
 
 void ReportPrintSettingHistogram(enum PrintSettingsBuckets setting) {
   UMA_HISTOGRAM_ENUMERATION("PrintPreview.PrintSettings", setting,
                             PRINT_SETTINGS_BUCKET_BOUNDARY);
 }
 
+void ReportPrintDocumentTypeHistogram(enum PrintDocumentTypeBuckets doctype) {
+  UMA_HISTOGRAM_ENUMERATION("PrintPreview.PrintDocumentType", doctype,
+                            PRINT_DOCUMENT_TYPE_BUCKET_BOUNDARY);
+}
+
 // Name of a dictionary field holding cloud print related data;
 const char kAppState[] = "appState";
 // Name of a dictionary field holding the initiator title.
 const char kInitiatorTitle[] = "initiatorTitle";
 // Name of a dictionary field holding the measurement system according to the
 // locale.
 const char kMeasurementSystem[] = "measurementSystem";
 // Name of a dictionary field holding the number format according to the locale.
 const char kNumberFormat[] = "numberFormat";
 // Name of a dictionary field specifying whether to print automatically in
@@ skipping 629 matching lines @@
   // before printing.
   UMA_HISTOGRAM_COUNTS("PrintPreview.RegeneratePreviewRequest.BeforePrint",
                        regenerate_preview_request_count_);
 
   std::unique_ptr<base::DictionaryValue> settings = GetSettingsDictionary(args);
   if (!settings)
     return;
 
   ReportPrintSettingsStats(*settings);
 
+  // Report whether the user printed a PDF or an HTML document.
+  ReportPrintDocumentTypeHistogram(print_preview_ui()->source_is_modifiable() ?
+                                   HTML_DOCUMENT : PDF_DOCUMENT);
+
   // Never try to add headers/footers here. It's already in the generated PDF.
   settings->SetBoolean(printing::kSettingHeaderFooterEnabled, false);
 
   bool print_to_pdf = false;
   bool is_cloud_printer = false;
   bool print_with_privet = false;
   bool print_with_extension = false;
 
   bool open_pdf_in_preview = false;
 #if defined(OS_MACOSX)
@@ skipping 900 matching lines @@
 
 void PrintPreviewHandler::UnregisterForGaiaCookieChanges() {
   if (gaia_cookie_manager_service_)
     gaia_cookie_manager_service_->RemoveObserver(this);
 }
 
 void PrintPreviewHandler::SetPdfSavedClosureForTesting(
     const base::Closure& closure) {
   pdf_file_saved_closure_ = closure;
 }