Allow fallback from https to http for component update checks.

components/update_client/ping_manager.h

Index: components/update_client/ping_manager.h
diff --git a/components/update_client/ping_manager.h b/components/update_client/ping_manager.h
index d5a6311d4cb1f352aff12e3127c433c7b2a19342..c907e7df2bbf0143158145926972cfae84180527 100644
--- a/components/update_client/ping_manager.h
+++ b/components/update_client/ping_manager.h
@@ -19,7 +19,11 @@ class PingManager {
   explicit PingManager(const scoped_refptr<Configurator>& config);
   virtual ~PingManager();
 
-  virtual void SendPing(const CrxUpdateItem* item);
+  // Sends a fire and forget ping for the |item|. Returns true if the
+  // ping is queued up and may be sent in the future, or false, if an error
+  // occurs right away. The ping itself is not persisted and it will be
+  // discarded if it can't be sent for any reason.
+  virtual bool SendPing(const CrxUpdateItem* item);
 
  private:
   const scoped_refptr<Configurator> config_;