AU: Verify delta payload signature and signed hash.

delta_performer_unittest.cc

Index: delta_performer_unittest.cc
diff --git a/delta_performer_unittest.cc b/delta_performer_unittest.cc
index 09a4c7d3e1807237c56af260a00df84eab22989a..8c7d2cd805c35f1e29782258b3145970e816def6 100755
--- a/delta_performer_unittest.cc
+++ b/delta_performer_unittest.cc
@@ -29,6 +29,7 @@ using std::string;
 using std::vector;
 
 extern const char* kUnittestPrivateKeyPath;
+extern const char* kUnittestPublicKeyPath;
 
 class DeltaPerformerTest : public ::testing::Test { };
 
@@ -255,6 +256,9 @@ TEST(DeltaPerformerTest, RunAsRootSmallImageTest) {
   EXPECT_TRUE(utils::ReadFile(old_kernel, &updated_kernel_partition));
   EXPECT_EQ(0, strncmp(&updated_kernel_partition[0], new_data_string,
                        strlen(new_data_string)));
+
+  EXPECT_TRUE(utils::FileExists(kUnittestPublicKeyPath));
+  EXPECT_TRUE(performer.VerifyPayload(kUnittestPublicKeyPath));
 }
 
 }  // namespace chromeos_update_engine