update_engine: Update libchrome APIS to r456626.

The new libchrome has been ported from Chromium and some APIs
have changed. Make necessary changes at call sites.

BUG=chromium:724678
CQ-DEPEND=CL:480928
Test: Build.

Change-Id: I01b70da87521d0884ed21acbd7ed3e0ff1e94357
Merged-In: I4dbaea4a2a19031375a8bf2415645a4f226dab57
diff --git a/connection_manager.cc b/connection_manager.cc
index f72d9e8..d15faf0 100644
--- a/connection_manager.cc
+++ b/connection_manager.cc
@@ -73,7 +73,7 @@
       if (device_policy->GetAllowedConnectionTypesForUpdate(&allowed_types)) {
         // The update setting is enforced by the device policy.
 
-        if (!ContainsKey(allowed_types, shill::kTypeCellular)) {
+        if (!base::ContainsKey(allowed_types, shill::kTypeCellular)) {
           LOG(INFO) << "Disabling updates over cellular connection as it's not "
                        "allowed in the device policy.";
           return false;