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/mock_partition_writer.h b/payload_consumer/mock_partition_writer.h
index b056010..0f21337 100644
--- a/payload_consumer/mock_partition_writer.h
+++ b/payload_consumer/mock_partition_writer.h
@@ -54,11 +54,7 @@
               (const InstallOperation&, ErrorCode*),
               (override));
   MOCK_METHOD(bool,
-              PerformSourceBsdiffOperation,
-              (const InstallOperation&, ErrorCode*, const void*, size_t),
-              (override));
-  MOCK_METHOD(bool,
-              PerformPuffDiffOperation,
+              PerformDiffOperation,
               (const InstallOperation&, ErrorCode*, const void*, size_t),
               (override));
 };