delta_generator: Include per-operation source hash.
This adds a src_sha256_hash field in the operation if minor version is 3.
Bug: 23182225
TEST=cros_workon_make update_engine --test
TEST=Generated a minor version 3 payload, the manifest is about 50% larger.
Change-Id: I0e363fca4de24bae64ac83930afdd42a6ddc21c9
diff --git a/payload_constants.cc b/payload_constants.cc
index cc18430..b831240 100644
--- a/payload_constants.cc
+++ b/payload_constants.cc
@@ -24,6 +24,7 @@
const uint32_t kFullPayloadMinorVersion = 0;
const uint32_t kInPlaceMinorPayloadVersion = 1;
const uint32_t kSourceMinorPayloadVersion = 2;
+const uint32_t kOpSrcHashMinorPayloadVersion = 3;
const char kLegacyPartitionNameKernel[] = "boot";
const char kLegacyPartitionNameRoot[] = "system";