Clean up NativeSmbFileShare.Re* UMAs

Removed and obsoleted NativeSmbFileShare.ReadDirectoryCount and
NativeSmbFileShare.ReadDirectoryDuration, which are no longer used with
the new smbfs implementation that is now enabled by default.

Extended expiry date for NativeSmbFileShare.RemountResult UMA to M94.

Bug: 1088968
Change-Id: I5272135376d22a3b1312de8e5e50f00c6e6b5181
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2418754
Commit-Queue: Josh Simmons <simmonsjosh@google.com>
Reviewed-by: Anand K Mistry <amistry@chromium.org>
Reviewed-by: Mark Pearson <mpearson@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#811559}

chrome/browser/chromeos/smb_client/smb_file_system.cc

@@ -108,15 +108,6 @@ void ConvertEntries(const smbprovider::DirectoryEntryListProto& entries_proto,
   }
 }
 
-// Metrics recording.
-void RecordReadDirectoryCount(int count) {
-  UMA_HISTOGRAM_COUNTS_100000("NativeSmbFileShare.ReadDirectoryCount", count);
-}
-
-void RecordReadDirectoryDuration(const base::TimeDelta& delta) {
-  UMA_HISTOGRAM_TIMES("NativeSmbFileShare.ReadDirectoryDuration", delta);
-}
-
 }  // namespace
 
 namespace smb_client {
@@ -641,9 +632,6 @@ void SmbFileSystem::HandleRequestReadDirectoryCallback(
   uint32_t batch_size = kReadDirectoryInitialBatchSize;
   storage::AsyncFileUtil::EntryList entry_list;
 
-  RecordReadDirectoryCount(entries.entries_size());
-  RecordReadDirectoryDuration(metrics_timer.Elapsed());
-
   // Loop through the entries and send when the desired batch size is hit.
   for (const smbprovider::DirectoryEntryProto& entry : entries.entries()) {
     entry_list.emplace_back(base::FilePath(entry.name()),
@@ -821,10 +809,6 @@ void SmbFileSystem::ProcessReadDirectoryResults(
                           std::move(metrics_timer));
     return;
   }
-
-  // Read Directory is complete, record metrics.
-  RecordReadDirectoryCount(entries_count);
-  RecordReadDirectoryDuration(metrics_timer.Elapsed());
 }
 
 AbortCallback SmbFileSystem::HandleSyncRedundantGetMetadata(

tools/metrics/histograms/histograms_xml/others/histograms.xml

@@ -8573,6 +8573,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="NativeSmbFileShare.ReadDirectoryCount" units="units"
     expires_after="M85">
+  <obsolete>
+    Removed in M87. No longer used with smbfs.
+  </obsolete>
   <owner>zentaro@chromium.org</owner>
   <summary>
     The number of entries read when calling ReadDirectory. This is recorded
@@ -8582,6 +8585,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram name="NativeSmbFileShare.ReadDirectoryDuration" units="ms"
     expires_after="M85">
+  <obsolete>
+    Removed in M87. No longer used with smbfs.
+  </obsolete>
   <owner>zentaro@chromium.org</owner>
   <summary>
     The duration of ReadDirectory call to SmbProvider in milliseconds. This is
@@ -8590,8 +8596,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="NativeSmbFileShare.RemountResult"
-    enum="NativeSmbFileShare_MountResult" expires_after="M85">
-  <owner>zentaro@chromium.org</owner>
+    enum="NativeSmbFileShare_MountResult" expires_after="M94">
+  <owner>simmonsjosh@google.com</owner>
+  <owner>src/chrome/browser/chromeos/smb_client/OWNERS</owner>
   <summary>
     The result of the Remount operation during startup. This is recorded after
     the D-Bus call to Remount returns.