Rewrite LogDog log viewer app.

web/inc/rpc/rpc-call.html

 <!--
   Copyright 2016 The LUCI Authors. All rights reserved.
   Use of this source code is governed under the Apache License, Version 2.0
   that can be found in the LICENSE file.
 -->
 
 <link rel="import" href="../bower_components/iron-ajax/iron-request.html">
 
 <!--
   The `rpc-call` is a single RPC call. Produced by <rpc-client>.
@@ skipping 184 matching lines @@
         this._ironRequest = document.createElement('iron-request');
         this._ironRequest.send(this.toRequestOptions());
         this.xhr = this._ironRequest.xhr;
         this._ironRequest.completes
           .then(this._done.bind(this, null))
           .catch(this._done.bind(this));
       },
 
       _done: function(error) {
         try {
-          if (error && typeof this.xhr.status !== 'number') {
+          var status = this.xhr.status;
+          if (error && typeof status !== 'number') {
             // We didn't receive the response.
             throw error;
           }
 
           var codeHeader = this.xhr.getResponseHeader('X-Prpc-Grpc-Code');
           if (!codeHeader) {
-            throw Error(
+            throw new luci.rpc.HttpError( status,
                 'Invalid response: no X-Prpc-Grpc-Code response header');
           }
 
           try {
             this._setCode(parseInt(codeHeader, 10));
             if (this.code == null || isNaN(this.code)) {
               throw Error('code is not defined');
             }
           } catch (e) {
-            throw Error(
+            throw new luci.rpc.HttpError( status,
                 'Invalid X-Prpc-Grpc-Code response header "' + codeHeader +
                 '": ' + e
             );
           }
 
           if (this.code !== luci.rpc.Code.OK) {
             throw new luci.rpc.GrpcError(this.code, this.xhr.responseText);
           }
 
           if (this._ironRequest.response == null) {
             throw Error('could not parse response');
           }
 
           this._setResponse(this._ironRequest.response);
           this._setError(null);
           this._resolveCompletes(this);
         } catch (e) {
           this._setResponse(null);
           this._setError(e);
           this._rejectCompletes(e);
         }
       }
     });
   </script>
 </dom-module>