PrintPreview: Added new histograms for print preview.

chrome/browser/ui/webui/print_preview_handler.h

 // Copyright (c) 2011 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.
 
 #ifndef CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_HANDLER_H_
 #pragma once
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 67 matching lines @@
 
   // Helper function to get the initiator tab for the print preview tab.
   TabContents* GetInitiatorTab();
 
   // Helper function to close the print preview tab.
   void ClosePrintPreviewTab();
 
   // Helper function to activate the initiator tab and close the preview tab.
   void ActivateInitiatorTabAndClosePreviewTab();
 
+  // Adds all the recorded stats taken so far to histogram counts.
+  void ReportStats();
+
   // Pointer to current print system.
   scoped_refptr<printing::PrintBackend> print_backend_;
 
   // The underlying dialog object.
   scoped_refptr<SelectFileDialog> select_file_dialog_;
 
   static FilePath* last_saved_path_;
 
+  // A count of how many requests received to regenerate preview data.
+  // Initialized to 0 then incremented and emitted to a histogram.
+  int regenerate_preview_request_count_;
+
+  // A count of how many requests received to show manage printers dialog.
+  int manage_printers_dialog_request_count_;
+
+  // A count of how many times print preview failed.
+  int print_preview_failed_count_;
+
+  // Whether we have already logged the number of printers this session.
+  bool has_logged_printers_count_;
+
   DISALLOW_COPY_AND_ASSIGN(PrintPreviewHandler);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_PRINT_PREVIEW_HANDLER_H_