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..cabb034d6145e27702aebdba92c15ffbddd12b09 100644
--- a/base/files/file_path_watcher_linux.cc
+++ b/base/files/file_path_watcher_linux.cc
@@ -10,6 +10,7 @@
 #include <sys/inotify.h>
 #include <sys/ioctl.h>
 #include <sys/select.h>
+#include <sys/stat.h>
 #include <unistd.h>
 
 #include <algorithm>
@@ -34,6 +35,7 @@
 #include "base/synchronization/lock.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_task_runner_handle.h"
+#include "base/time/time.h"
 #include "base/trace_event/trace_event.h"
 
 namespace base {
@@ -403,7 +405,10 @@ void FilePathWatcherImpl::OnFilePathChanged(InotifyReader::Watch fired_watch,
     if (target_changed ||
         (change_on_target_path && deleted) ||
         (change_on_target_path && created && PathExists(target_))) {
-      if (!did_update) {
+      struct stat child_stat;
+      stat(target_.Append(watch_entry.subdir).Append(child).value().c_str(),
+           &child_stat);
+      if (!did_update && S_ISDIR(child_stat.st_mode)) {
         UpdateRecursiveWatches(fired_watch, is_dir);
         did_update = true;
       }