Add LoadComponent API in ImageLoader dbus adapter.

chromeos/dbus/fake_image_loader_client.h

Index: chromeos/dbus/fake_image_loader_client.h
diff --git a/chromeos/dbus/fake_image_loader_client.h b/chromeos/dbus/fake_image_loader_client.h
index 5d98797e9d6720c9fb34d7b81665ed085aa7adf4..ee0c2d66422f9ace2f31c3e77ef475a7f2b99906 100644
--- a/chromeos/dbus/fake_image_loader_client.h
+++ b/chromeos/dbus/fake_image_loader_client.h
@@ -26,6 +26,8 @@ class CHROMEOS_EXPORT FakeImageLoaderClient : public ImageLoaderClient {
                          const std::string& version,
                          const std::string& component_folder_abs_path,
                          const BoolDBusMethodCallback& callback) override;
+  void LoadComponent(const std::string& name,
+                     const StringDBusMethodCallback& callback) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FakeImageLoaderClient);