AU: Detect and report public key verify failures, but continue updating.

update_attempter.cc

Index: update_attempter.cc
diff --git a/update_attempter.cc b/update_attempter.cc
index c9ee712809e30d7b39680bc1620dddb1d0366529..f56c0d1275ffd3dca0aeb1e720b5ac59e342a3e4 100644
--- a/update_attempter.cc
+++ b/update_attempter.cc
@@ -32,6 +32,7 @@
 
 using base::TimeDelta;
 using base::TimeTicks;
+using google::protobuf::NewPermanentCallback;
 using std::make_pair;
 using std::tr1::shared_ptr;
 using std::string;
@@ -188,6 +189,21 @@ void UpdateAttempter::Update(const std::string& app_version,
   shared_ptr<DownloadAction> download_action(
       new DownloadAction(prefs_, new MultiRangeHTTPFetcher(
           new LibcurlHttpFetcher(GetProxyResolver()))));
+  // This action is always initially in place to warn OS vendor of a
+  // signature failure.  If it's not needed, it will be told to skip.
+  shared_ptr<OmahaRequestAction> download_signature_warning(
+      new OmahaRequestAction(
+          prefs_,
+          omaha_request_params_,
+          new OmahaEvent(
+              OmahaEvent::kTypeUpdateDownloadFinished,
+              OmahaEvent::kResultError,
+              kActionCodeDownloadPayloadPubKeyVerificationError),
+          new LibcurlHttpFetcher(GetProxyResolver())));
+  download_action->set_skip_reporting_signature_fail(
+      NewPermanentCallback(download_signature_warning.get(),
+                           &OmahaRequestAction::set_should_skip,
+                           true));
   shared_ptr<OmahaRequestAction> download_finished_action(
       new OmahaRequestAction(prefs_,
                              omaha_request_params_,
@@ -217,6 +233,7 @@ void UpdateAttempter::Update(const std::string& app_version,
       kernel_filesystem_copier_action));
   actions_.push_back(shared_ptr<AbstractAction>(download_started_action));
   actions_.push_back(shared_ptr<AbstractAction>(download_action));
+  actions_.push_back(shared_ptr<AbstractAction>(download_signature_warning));
   actions_.push_back(shared_ptr<AbstractAction>(download_finished_action));
   actions_.push_back(shared_ptr<AbstractAction>(filesystem_verifier_action));
   actions_.push_back(shared_ptr<AbstractAction>(