[fsp] Extract ObservedEntry and ObservedEntries to a separate file.

chrome/browser/chromeos/file_system_provider/service.h

Index: chrome/browser/chromeos/file_system_provider/service.h
diff --git a/chrome/browser/chromeos/file_system_provider/service.h b/chrome/browser/chromeos/file_system_provider/service.h
index 77c39f2ed4ae0ca50a9ae267aa4f3711042a8fe0..d81b57e2628106860500cd05b6f5d7a5aac6b9f9 100644
--- a/chrome/browser/chromeos/file_system_provider/service.h
+++ b/chrome/browser/chromeos/file_system_provider/service.h
@@ -138,9 +138,11 @@ class Service : public KeyedService,
       const base::Closure& callback) override;
   virtual void OnObservedEntryTagUpdated(
       const ProvidedFileSystemInfo& file_system_info,
-      const base::FilePath& observed_path) override;
+      const base::FilePath& observed_path,
+      const std::string& tag) override;
   virtual void OnObservedEntryListChanged(
-      const ProvidedFileSystemInfo& file_system_info) override;
+      const ProvidedFileSystemInfo& file_system_info,
+      const ObservedEntries& observed_entries) override;
 
  private:
   // Key is a pair of an extension id and file system id, which makes it