Use one big array for all blobs instead of ranks.

lib/ChunkedBlob.js

@@ -10,26 +10,16 @@ export default class ChunkedBlob {
 
   constructor() {
     this.size = 0
-    this.ranks = [[]]
+    this.ranks = []
   }
 
   add(b) {
     this.size += blobLength(b)
-    this.ranks[0].push(b)
-
-    for (let i = 0; i < this.ranks.length; i++) {
-      let rank = this.ranks[i]
-      if (rank.length === rankSize) {
-        this.ranks[i + 1] = this.ranks[i + 1] || []
-        this.ranks[i + 1].push(new Blob(rank))
-        this.ranks[i] = []
-      }
-    }
+    this.ranks.push(b)
   }
 
   toBlob() {
-    let allRanks = [].concat(...this.ranks)
-    return new Blob(allRanks)
+    return new Blob(this.ranks)
   }
 
-}
+}