Only update watches when directories change.

base/files/file_path_watcher_linux.cc

Index: base/files/file_path_watcher_linux.cc
diff --git a/base/files/file_path_watcher_linux.cc b/base/files/file_path_watcher_linux.cc
index 2444b4453db2ce76c3745c1ec686efd991f29397..90164c3374f59dada2402f7e2d0f954718894400 100644
--- a/base/files/file_path_watcher_linux.cc
+++ b/base/files/file_path_watcher_linux.cc
@@ -521,6 +521,10 @@ void FilePathWatcherImpl::UpdateRecursiveWatches(
     return;
   }
 
+  // Underneath |target_|, only directory changes trigger watch updates.
+  if (!is_dir && fired_watch != InotifyReader::kInvalidWatch)
+    return;
+
   // Check to see if this is a forced update or if some component of |target_|
   // has changed. For these cases, redo the watches for |target_| and below.
   if (!ContainsKey(recursive_paths_by_watch_, fired_watch)) {

[Shuhei Takahashi, 2016/09/08 05:10:52]

Hmm, reordering the checks is fragile and I'm afraid future changes may cause
regression unexpectedly. I prefer proper fix here:

if (!ContainsKey(recursive_paths_by_watch_, fired_watch) &&
    fired_watch != watches_.back().watch)

[dspaid, 2016/09/09 02:00:55]

Done.

@@ -528,10 +532,6 @@ void FilePathWatcherImpl::UpdateRecursiveWatches(
     return;
   }
 
-  // Underneath |target_|, only directory changes trigger watch updates.
-  if (!is_dir)
-    return;
-
   const FilePath& changed_dir = recursive_paths_by_watch_[fired_watch];
 
   std::map<FilePath, InotifyReader::Watch>::iterator start_it =