Catch the sign zip error earlier to prevent invalid private key crash Chrome.

chrome/browser/extensions/extension_service_unittest.cc

Index: chrome/browser/extensions/extension_service_unittest.cc
diff --git a/chrome/browser/extensions/extension_service_unittest.cc b/chrome/browser/extensions/extension_service_unittest.cc
index e8f452b98cd7b8620428c98f007c2e24424ace7f..f7de3a706b5c851589097b57a00eb0cbf46613a0 100644
--- a/chrome/browser/extensions/extension_service_unittest.cc
+++ b/chrome/browser/extensions/extension_service_unittest.cc
@@ -2202,6 +2202,12 @@ TEST_F(ExtensionServiceTest, PackExtension) {
   creator.reset(new ExtensionCreator());
   ASSERT_FALSE(creator->Run(temp_dir2.path(), crx_path, privkey_path,
                             base::FilePath(), ExtensionCreator::kOverwriteCRX));
+
+  // Try packing with an invalid private key. Should fail.
+  base::FilePath invalid_private_key = data_dir_.AppendASCII("invalid.pem");
+  creator.reset(new ExtensionCreator());
+  ASSERT_FALSE(creator->Run(input_directory, crx_path, invalid_private_key,
+                            base::FilePath(), ExtensionCreator::kOverwriteCRX));
 }
 
 // Test Packaging and installing an extension whose name contains punctuation.