Add brief comments and reorganize metrics helpers

This change adds comments to make it clear which functions are used for
reporting metrics and moves them to the bottom of the class.

Bug: chromium:757625
Change-Id: I07f82bb50df9ac77afc4d235d802c576aa326bbc
Reviewed-on: https://chromium-review.googlesource.com/1102088Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Commit-Queue: Zentaro Kavanagh <zentaro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570131}

chrome/browser/chromeos/smb_client/smb_file_system.cc

@@ -67,6 +67,7 @@ bool RequestedThumbnail(ProvidedFileSystemInterface::MetadataFieldMask fields) {
          ProvidedFileSystemInterface::MetadataField::METADATA_FIELD_THUMBNAIL;
 }
 
+// Metrics recording.
 void RecordReadDirectoryCount(int count) {
   UMA_HISTOGRAM_COUNTS_100000("NativeSmbFileShare.ReadDirectoryCount", count);
 }

chrome/browser/chromeos/smb_client/smb_service.cc

@@ -32,6 +32,7 @@ bool ContainsAt(const std::string& username) {
   return username.find('@') != std::string::npos;
 }
 
+// Metric recording functions.
 void RecordMountResult(SmbMountResult result) {
   DCHECK_LE(result, SmbMountResult::kMaxValue);
   UMA_HISTOGRAM_ENUMERATION("NativeSmbFileShare.MountResult", result);
@@ -268,13 +269,6 @@ void SmbService::FireMountCallback(MountResponse callback,
   std::move(callback).Run(result);
 }
 
-void SmbService::RecordMountCount() const {
-  const std::vector<ProvidedFileSystemInfo> file_systems =
-      GetProviderService()->GetProvidedFileSystemInfoList(provider_id_);
-  UMA_HISTOGRAM_COUNTS_100("NativeSmbFileShare.MountCount",
-                           file_systems.size());
-}
-
 void SmbService::RegisterHostLocators() {
   SetUpMdnsHostLocator();
 }
@@ -283,5 +277,12 @@ void SmbService::SetUpMdnsHostLocator() {
   share_finder_->RegisterHostLocator(std::make_unique<MDnsHostLocator>());
 }
 
+void SmbService::RecordMountCount() const {
+  const std::vector<ProvidedFileSystemInfo> file_systems =
+      GetProviderService()->GetProvidedFileSystemInfoList(provider_id_);
+  UMA_HISTOGRAM_COUNTS_100("NativeSmbFileShare.MountCount",
+                           file_systems.size());
+}
+
 }  // namespace smb_client
 }  // namespace chromeos

chrome/browser/chromeos/smb_client/smb_service.h

@@ -124,14 +124,15 @@ class SmbService : public KeyedService,
   // Fires |callback| with |result|.
   void FireMountCallback(MountResponse callback, SmbMountResult result);
 
-  void RecordMountCount() const;
-
   // Registers host locators for |share_finder_|.
   void RegisterHostLocators();
 
   // Set up Multicast DNS host locator.
   void SetUpMdnsHostLocator();
 
+  // Records metrics on the number of SMB mounts a user has.
+  void RecordMountCount() const;
+
   const ProviderId provider_id_;
   Profile* profile_;
   std::unique_ptr<TempFileManager> temp_file_manager_;