[remoting host] Only watch for material changes to NSS DB files

remoting/host/linux/certificate_watcher.h

Index: remoting/host/linux/certificate_watcher.h
diff --git a/remoting/host/linux/certificate_watcher.h b/remoting/host/linux/certificate_watcher.h
index 5dee61d3cff6d6e6f1274751e996d94c36228613..65938e0ae15fa3ddcf651a97d285b8607bb96a2c 100644
--- a/remoting/host/linux/certificate_watcher.h
+++ b/remoting/host/linux/certificate_watcher.h
@@ -17,6 +17,8 @@
 
 namespace remoting {
 
+class CertDbContentWatcher;
+
 // This class watches the cert database and notifies the host to restart when
 // a change of the database is detected. The runner script will restart the host
 // when the host is killed then the new host will capture any new changes of the
@@ -56,21 +58,14 @@ class CertificateWatcher : public remoting::HostStatusObserver {
   void SetWatchPathForTests(const base::FilePath& watch_path);
 
  private:
+  friend class CertDbContentWatcher;
+
   // Returns true if the watcher has started.
   bool is_started() const;
 
-  // Callback passed to |file_watcher_|. Runs in IO thread.
-  static void OnCertDirectoryChanged(
-      scoped_refptr<base::SingleThreadTaskRunner> network_task_runner,
-      base::WeakPtr<CertificateWatcher> watcher_, const base::FilePath& path,
-      bool error);
-
-  // Runs in the caller's thread.
-  void DirectoryChanged(const base::FilePath& path, bool error);
-
-  // Called by |restart_timer_| when it's time to reset the host.
-  // It will defer restart if |inhibit_restart_scheduled_| flag is set to true.
-  void OnTimer();
+  // Runs in the caller's thread. It will defer restarting the host if
+  // |inhibit_restart_scheduled_| flag is set to true.
+  void DatabaseChanged();
 
   // Reference to the monitor
   base::WeakPtr<HostStatusMonitor> monitor_;
@@ -91,15 +86,13 @@ class CertificateWatcher : public remoting::HostStatusObserver {
   // Path of the certificate files/directories.
   base::FilePath cert_watch_path_;
 
-  // The file watcher to watch changes inside the certificate folder.
-  std::unique_ptr<base::FilePathWatcher> file_watcher_;
+  // The watcher implementation that watches the files on the IO thread.
+  std::unique_ptr<CertDbContentWatcher> content_watcher_;
 
-  // The time to wait to restart when it is scheduled.
+  // The time to wait before re-reading the DB files after a change is
+  // detected.
   base::TimeDelta delay_;
 
-  // Timer to delay the restart action.
-  std::unique_ptr<base::DelayTimer> restart_timer_;
-
   base::WeakPtrFactory<CertificateWatcher> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CertificateWatcher);