Re-enable UMA metric WinJumplist.CreateIconFilesCount

chrome/browser/win/jumplist.cc

 // Copyright 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/win/jumplist.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 222 matching lines @@
     --user_max_items_adjusted;
 
   size_t most_visited_items =
       MulDiv(user_max_items_adjusted, kMostVisited, kTotal);
   size_t recently_closed_items = user_max_items_adjusted - most_visited_items;
   if (recently_closed_pages.size() < recently_closed_items) {
     most_visited_items += recently_closed_items - recently_closed_pages.size();
     recently_closed_items = recently_closed_pages.size();
   }
 
+  // Record the number of icons created per JumpList update.

[grt (UTC plus 2), 2017/05/01 08:44:38]

nit:
  // Record the desired number of icons to create in this JumpList update.

[chengx, 2017/05/01 18:08:22]

Done.

+  int icons_to_create = 0;
+
   if (most_visited_pages_have_updates) {
     // Delete the content in JumpListIconsMostVisited folder and log the results
     // to UMA.
     base::FilePath icon_dir_most_visited = icon_dir.DirName().Append(
         icon_dir.BaseName().value() + FILE_PATH_LITERAL("MostVisited"));
 
     DeleteDirectoryContentAndLogResults(icon_dir_most_visited,
                                         kFileDeleteLimit);
 
     // If the directory doesn't exist (we have tried to create it in
     // DeleteDirectoryContentAndLogResults) or is not empty, skip updating the
     // jumplist icons. The jumplist links should be updated anyway, as it
     // doesn't involve disk IO. In this case, Chrome's icon will be used for the
     // new links.
     if (base::DirectoryExists(icon_dir_most_visited) &&
         base::IsDirectoryEmpty(icon_dir_most_visited)) {
       // Create icon files for shortcuts in the "Most Visited" category.
       CreateIconFiles(icon_dir_most_visited, most_visited_pages,
                       most_visited_items);
+
+      icons_to_create +=
+          std::min(most_visited_pages.size(), most_visited_items);
     }
   }
 
   if (recently_closed_pages_have_updates) {
     // Delete the content in JumpListIconsRecentClosed folder and log the
     // results to UMA.
     base::FilePath icon_dir_recent_closed = icon_dir.DirName().Append(
         icon_dir.BaseName().value() + FILE_PATH_LITERAL("RecentClosed"));
 
     DeleteDirectoryContentAndLogResults(icon_dir_recent_closed,
                                         kFileDeleteLimit);
 
     if (base::DirectoryExists(icon_dir_recent_closed) &&
         base::IsDirectoryEmpty(icon_dir_recent_closed)) {
       // Create icon files for shortcuts in the "Recently Closed" category.
       CreateIconFiles(icon_dir_recent_closed, recently_closed_pages,
                       recently_closed_items);
+
+      icons_to_create +=
+          std::min(recently_closed_pages.size(), recently_closed_items);
     }
   }
 
   // TODO(chengx): Remove the UMA histogram after fixing http://crbug.com/40407.
+  UMA_HISTOGRAM_COUNTS_100("WinJumplist.CreateIconFilesCount", icons_to_create);
+
+  // TODO(chengx): Remove the UMA histogram after fixing http://crbug.com/40407.
   SCOPED_UMA_HISTOGRAM_TIMER("WinJumplist.UpdateJumpListDuration");
 
   // Update the "Most Visited" category of the JumpList if it exists.
   // This update request is applied into the JumpList when we commit this
   // transaction.
   if (!jumplist_updater.AddCustomCategory(
           l10n_util::GetStringUTF16(IDS_NEW_TAB_MOST_VISITED),
           most_visited_pages, most_visited_items)) {
     return false;
   }
@@ skipping 408 matching lines @@
 void JumpList::TopSitesLoaded(history::TopSites* top_sites) {
 }
 
 void JumpList::TopSitesChanged(history::TopSites* top_sites,
                                ChangeReason change_reason) {
   top_sites->GetMostVisitedURLs(
       base::Bind(&JumpList::OnMostVisitedURLsAvailable,
                  weak_ptr_factory_.GetWeakPtr()),
       false);
 }