Move FilePathWatcher to base/files.

chrome/browser/user_style_sheet_watcher.cc

Index: chrome/browser/user_style_sheet_watcher.cc
diff --git a/chrome/browser/user_style_sheet_watcher.cc b/chrome/browser/user_style_sheet_watcher.cc
index 516501d6c7c8c3002490ecf489fecd6b40912970..049479f4788bd48e715ce9277ddf07274e5e0059 100644
--- a/chrome/browser/user_style_sheet_watcher.cc
+++ b/chrome/browser/user_style_sheet_watcher.cc
@@ -36,7 +36,7 @@ const char kUserStyleSheetFile[] = "Custom.css";
 // UserStyleSheetWatcher and its FilePathWatcher may be destroyed while a
 // callback to UserStyleSheetLoader is in progress, in which case the
 // UserStyleSheetLoader object outlives the watchers.
-class UserStyleSheetLoader : public FilePathWatcher::Delegate {
+class UserStyleSheetLoader : public base::files::FilePathWatcher::Delegate {
  public:
   UserStyleSheetLoader();
   virtual ~UserStyleSheetLoader() {}
@@ -145,7 +145,7 @@ void UserStyleSheetWatcher::Init() {
   }
 
   if (!file_watcher_.get()) {
-    file_watcher_.reset(new FilePathWatcher);
+    file_watcher_.reset(new base::files::FilePathWatcher);
     FilePath style_sheet_file = profile_path_.AppendASCII(kStyleSheetDir)
                                              .AppendASCII(kUserStyleSheetFile);
     if (!file_watcher_->Watch(