Review fixes

Author: stanley-cheung

javascript/net/grpc/web/request.js

@@ -41,7 +41,7 @@ class Request {
    */
   getCallOptions() {}
 
-   /**
+  /**
    * @param {string} key
    * @param {string} value
    * @return {!Request<REQUEST, RESPONSE>}

javascript/net/grpc/web/streambodyclientreadablestream.js

@@ -278,6 +278,7 @@ class StreamBodyClientReadableStream {
       for (let i = 0; i < bytes.length; i++) {
         byteSource += String.fromCharCode(bytes[i]);
       }
+      return byteSource;
     } else {
       return this.xhr_.getResponse();
     }