Add skeleton for zucchini patch

Also consolidates the code in partition writer to call patch functions
in one places.

Bug: 197361113
Test: TH
Change-Id: If6b5b9b6393888e67854b7130ae9a63e2fec482a
diff --git a/payload_consumer/delta_performer.h b/payload_consumer/delta_performer.h
index 30f5e9c..de6f448 100644
--- a/payload_consumer/delta_performer.h
+++ b/payload_consumer/delta_performer.h
@@ -267,10 +267,8 @@
   bool PerformZeroOrDiscardOperation(const InstallOperation& operation);
   bool PerformSourceCopyOperation(const InstallOperation& operation,
                                   ErrorCode* error);
-  bool PerformSourceBsdiffOperation(const InstallOperation& operation,
-                                    ErrorCode* error);
-  bool PerformPuffDiffOperation(const InstallOperation& operation,
-                                ErrorCode* error);
+  bool PerformDiffOperation(const InstallOperation& operation,
+                            ErrorCode* error);
 
   // Extracts the payload signature message from the current |buffer_| if the
   // offset matches the one specified by the manifest. Returns whether the