Prefer opening PDF downloads in the browser.

chrome/browser/download/download_stats.h

 // Copyright 2013 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_DOWNLOAD_DOWNLOAD_STATS_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_STATS_H_
 
 #include "content/public/browser/download_danger_type.h"
 
 // Record the total number of items and the number of in-progress items showing
@@ skipping 38 matching lines @@
 
   // The download was initiated by the PDF plugin..
   DOWNLOAD_INITIATED_BY_PDF_SAVE,
 
   // The download was initiated by chrome.downloads.download().
   DOWNLOAD_INITIATED_BY_EXTENSION,
 
   CHROME_DOWNLOAD_SOURCE_LAST_ENTRY,
 };
 
+// How a download was opened. Note that a download could be opened multiple
+// times.
+enum ChromeDownloadOpenMethod {
+  // The download was opened using the platform handler. There was no special
+  // handling for this download.
+  DOWNLOAD_OPEN_METHOD_DEFAULT_PLATFORM = 0,
+
+  // The download was opened using the browser bypassing the system handler.
+  DOWNLOAD_OPEN_METHOD_DEFAULT_BROWSER,
+
+  // The user chose to open the download using the system handler even though
+  // the preferred method was to open the download using the browser.
+  DOWNLOAD_OPEN_METHOD_USER_PLATFORM,
+
+  DOWNLOAD_OPEN_METHOD_LAST_ENTRY
+};
+
 // Increment one of the above counts.
 void RecordDownloadCount(ChromeDownloadCountTypes type);
 
 // Record initiation of a download from a specific source.
 void RecordDownloadSource(ChromeDownloadSource source);
 
 // Record that the user opened the confirmation dialog for a dangerous download.
 void RecordOpenedDangerousConfirmDialog(
     content::DownloadDangerType danger_type);
 
+// Record how a download was opened.
+void RecordDownloadOpenMethod(ChromeDownloadOpenMethod open_method);
+
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_STATS_H_