Add support for almost-recursive watches in Linux DirectoryWatcher

base/directory_watcher_win.cc

Index: base/directory_watcher_win.cc
diff --git a/base/directory_watcher_win.cc b/base/directory_watcher_win.cc
index e75fe575cb4a90d1f5537753ddd2ba86835bf7d1..b6eb9ab5c1ca6deca2d28e4d56fb95257021e4fb 100644
--- a/base/directory_watcher_win.cc
+++ b/base/directory_watcher_win.cc
@@ -18,7 +18,7 @@ class DirectoryWatcherImpl : public DirectoryWatcher::PlatformDelegate,
   virtual ~DirectoryWatcherImpl();
 
   virtual bool Watch(const FilePath& path, DirectoryWatcher::Delegate* delegate,
-                     bool recursive);
+                     MessageLoop* backend_loop, bool recursive);
 
   // Callback from MessageLoopForIO.
   virtual void OnObjectSignaled(HANDLE object);
@@ -44,7 +44,8 @@ DirectoryWatcherImpl::~DirectoryWatcherImpl() {
 }
 
 bool DirectoryWatcherImpl::Watch(const FilePath& path,
-    DirectoryWatcher::Delegate* delegate, bool recursive) {
+                                 DirectoryWatcher::Delegate* delegate,
+                                 MessageLoop* backend_loop, bool recursive) {
   DCHECK(path_.value().empty());  // Can only watch one path.
 
   handle_ = FindFirstChangeNotification(