[fsp] Add support for observing entries and notifying about changes.

chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h

Index: chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h
diff --git a/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h b/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h
index c2df097c9199e96988ee66762e91a46f11479870..8f35041158d3c957147e7c6618fb1695e99b3c41 100644
--- a/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h
+++ b/chrome/browser/chromeos/extensions/file_system_provider/file_system_provider_api.h
@@ -40,6 +40,16 @@ class FileSystemProviderGetAllFunction : public ChromeSyncExtensionFunction {
   virtual bool RunSync() override;
 };
 
+class FileSystemProviderNotifyFunction : public ChromeSyncExtensionFunction {
+ public:
+  DECLARE_EXTENSION_FUNCTION("fileSystemProvider.notify",
+                             FILESYSTEMPROVIDER_NOTIFY)
+
+ protected:
+  virtual ~FileSystemProviderNotifyFunction() {}
+  virtual bool RunSync() OVERRIDE;
+};
+
 class FileSystemProviderInternalUnmountRequestedSuccessFunction
     : public FileSystemProviderInternalFunction {
  public: