Add support for refreshing contents of providers which don't support watchers.

chrome/browser/chromeos/file_system_provider/service.cc

Index: chrome/browser/chromeos/file_system_provider/service.cc
diff --git a/chrome/browser/chromeos/file_system_provider/service.cc b/chrome/browser/chromeos/file_system_provider/service.cc
index 88e37649ce493bd1a8f66ba8ecfbfb4d260f0018..8766a8af4f0566424c319540c323aed2cbf79d1f 100644
--- a/chrome/browser/chromeos/file_system_provider/service.cc
+++ b/chrome/browser/chromeos/file_system_provider/service.cc
@@ -172,10 +172,12 @@ base::File::Error Service::MountFileSystemInternal(
   //   supports_notify_tag = false
   //   mount_path = /provided/b33f1337-hello_world-5aa5
   //   configurable = true
+  //   watchable = true
   //   source = SOURCE_FILE
   ProvidedFileSystemInfo file_system_info(
       extension_id, options, mount_path,
       provider_info.capabilities.configurable(),
+      provider_info.capabilities.watchable(),
       provider_info.capabilities.source());
 
   ProvidedFileSystemInterface* file_system =