Report some more UMAs for an offline page is removed

BUG=491352

Review URL: https://codereview.chromium.org/1439173003

Cr-Commit-Position: refs/heads/master@{#359767}

2 files changed, 71 insertions, 5 deletions

diff --git a/components/offline_pages/offline_page_model.cc b/components/offline_pages/offline_page_model.cc
index 1453004..7b0922e 100644
--- a/components/offline_pages/offline_page_model.cc
+++ b/components/offline_pages/offline_page_model.cc
@@ -540,17 +540,43 @@ void OfflinePageModel::OnRemoveOfflinePagesDone(
   // Delete the offline page from the in memory cache regardless of success in
   // store.
   base::Time now = base::Time::Now();
+  int64 total_size = 0;
   for (int64 bookmark_id : bookmark_ids) {
     auto iter = offline_pages_.find(bookmark_id);
     if (iter == offline_pages_.end())
       continue;
-    UMA_HISTOGRAM_CUSTOM_COUNTS("OfflinePages.PageLifetime",
-                                (now - iter->second.creation_time).InMinutes(),
-                                1,
-                                base::TimeDelta::FromDays(365).InMinutes(),
-                                100);
+    total_size += iter->second.file_size;
+    UMA_HISTOGRAM_CUSTOM_COUNTS(
+        "OfflinePages.PageLifetime",
+        (now - iter->second.creation_time).InMinutes(),
+        1,
+        base::TimeDelta::FromDays(365).InMinutes(),
+        100);
+    UMA_HISTOGRAM_CUSTOM_COUNTS(
+        "OfflinePages.DeletePage.TimeSinceLastOpen",
+        (now - iter->second.last_access_time).InMinutes(),
+        1,
+        base::TimeDelta::FromDays(365).InMinutes(),
+        100);
+    UMA_HISTOGRAM_CUSTOM_COUNTS(
+        "OfflinePages.DeletePage.LastOpenToCreated",
+        (iter->second.last_access_time - iter->second.creation_time).
+            InMinutes(),
+        1,
+        base::TimeDelta::FromDays(365).InMinutes(),
+        100);
+    UMA_HISTOGRAM_MEMORY_KB(
+        "OfflinePages.DeletePage.PageSize", iter->second.file_size / 1024);
+    UMA_HISTOGRAM_COUNTS(
+        "OfflinePages.DeletePage.AccessCount", iter->second.access_count);
     offline_pages_.erase(iter);
   }
+  if (bookmark_ids.size() > 1) {
+    UMA_HISTOGRAM_COUNTS(
+        "OfflinePages.BatchDelete.Count", bookmark_ids.size());
+    UMA_HISTOGRAM_MEMORY_KB(
+        "OfflinePages.BatchDelete.TotalPageSize", total_size / 1024);
+  }
   // Deleting multiple pages always succeeds when it gets to this point.
   InformDeletePageDone(
       callback,
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index d52d773..e4c9971 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -29828,11 +29828,31 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="OfflinePages.BatchDelete.Count">
+  <owner>jianli@chromium.org</owner>
+  <summary>Number of offline pages that are deleted in a batch.</summary>
+</histogram>
+
+<histogram name="OfflinePages.BatchDelete.TotalPageSize" units="KB">
+  <owner>jianli@chromium.org</owner>
+  <summary>
+    Total size, in kilobytes, of all offline pages that are deleted in a batch.
+  </summary>
+</histogram>
+
 <histogram name="OfflinePages.ClearAllStatus" enum="OfflinePagesClearAllStatus">
   <owner>jianli@chromium.org</owner>
   <summary>Status code of wiping out the offline page data.</summary>
 </histogram>
 
+<histogram name="OfflinePages.DeletePage.AccessCount">
+  <owner>jianli@chromium.org</owner>
+  <summary>
+    Number of accesses to the offline page since its creation. This is reported
+    when the offline page was deleted.
+  </summary>
+</histogram>
+
 <histogram name="OfflinePages.DeletePage.FreeSpaceMB" units="MB">
   <owner>jianli@chromium.org</owner>
   <summary>
@@ -29867,6 +29887,26 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="OfflinePages.DeletePage.LastOpenToCreated" units="minutes">
+  <owner>jianli@chromium.org</owner>
+  <summary>
+    Length of time between when an offline page was created and was opened last
+    time. This is reported when the page was deleted.
+  </summary>
+</histogram>
+
+<histogram name="OfflinePages.DeletePage.PageSize" units="KB">
+  <owner>jianli@chromium.org</owner>
+  <summary>Size of the offline page, in kilobytes, that was deleted.</summary>
+</histogram>
+
+<histogram name="OfflinePages.DeletePage.TimeSinceLastOpen" units="minutes">
+  <owner>jianli@chromium.org</owner>
+  <summary>
+    Length of time between when an offline page was last opened and was deleted.
+  </summary>
+</histogram>
+
 <histogram name="OfflinePages.DeletePageResult"
     enum="OfflinePagesDeletePageResult">
   <owner>jianli@chromium.org</owner>