Add additional Schedule heartbeat calls.

sdk/lib/_internal/pub/lib/src/hosted_source.dart

Index: sdk/lib/_internal/pub/lib/src/hosted_source.dart
diff --git a/sdk/lib/_internal/pub/lib/src/hosted_source.dart b/sdk/lib/_internal/pub/lib/src/hosted_source.dart
index 194b6e0cd6ff435b13aee5d365e98c3e3953f452..17b18399cb209e16c3066aa69418202f37d0c0f0 100644
--- a/sdk/lib/_internal/pub/lib/src/hosted_source.dart
+++ b/sdk/lib/_internal/pub/lib/src/hosted_source.dart
@@ -36,13 +36,10 @@ class HostedSource extends Source {
 
     log.io("Get versions from $url.");
     return httpClient.read(url).then((body) {
-      log.io("Versions JSON from $url: $body.");
       var doc = json.parse(body);
-      var versions = doc['versions']
+      return doc['versions']
           .map((version) => new Version.parse(version))
           .toList();
-      log.io("Versions from $url: $versions.");
-      return versions;
     }).catchError((ex) {
       var parsed = _parseDescription(description);
       _throwFriendlyError(ex, parsed.first, parsed.last);