Add support for almost-recursive watches in Linux DirectoryWatcher

base/directory_watcher_stub.cc

Index: base/directory_watcher_stub.cc
diff --git a/base/directory_watcher_stub.cc b/base/directory_watcher_stub.cc
index a92a84c7ccd0fb7b213b18dd0eadc096f62ea56a..92cc5ffde7fd0c8936ef5b911004c854888e3513 100644
--- a/base/directory_watcher_stub.cc
+++ b/base/directory_watcher_stub.cc
@@ -10,7 +10,7 @@
 class DirectoryWatcherImpl : public DirectoryWatcher::PlatformDelegate {
  public:
   virtual bool Watch(const FilePath& path, DirectoryWatcher::Delegate* delegate,
-                     bool recursive) {
+                     MessageLoop* backend_loop, bool recursive) {
     return false;
   }
 };