blimp: Use stl utilities from the base namespace

blimp/net/blob_channel/blob_channel_sender_impl.cc

Index: blimp/net/blob_channel/blob_channel_sender_impl.cc
diff --git a/blimp/net/blob_channel/blob_channel_sender_impl.cc b/blimp/net/blob_channel/blob_channel_sender_impl.cc
index 84dec6ccac70d8164800d56a0addeccfaab74349..7baf09fec2051b24b1dfeb51a53c1a73af44ba5d 100644
--- a/blimp/net/blob_channel/blob_channel_sender_impl.cc
+++ b/blimp/net/blob_channel/blob_channel_sender_impl.cc
@@ -31,7 +31,7 @@ BlobChannelSenderImpl::GetCachedBlobIds() const {
     CacheStateEntry next_output;
     next_output.id = cached_id;
     next_output.was_delivered =
-        ContainsKey(receiver_cache_contents_, cached_id);
+        base::ContainsKey(receiver_cache_contents_, cached_id);
     output.push_back(next_output);
   }
   return output;