Expand the functionality of the BudgetDatabase.

chrome/browser/budget_service/budget.proto

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 syntax = "proto2";
 
 package budget_service;
 
 // Chrome requires this.
 option optimize_for = LITE_RUNTIME;
 
 // Next available id: 3
 message Budget {
   // How much budget the origin needs to accumulate before it will be allowed to
   // perform another budget action.
   optional double debt = 1;
 
   // The sequence of budget chunks and their expiration times.
   repeated BudgetChunk budget = 2;
 }
 
 // Next available id: 3
 message BudgetChunk {
   // The amount of budget remaining in this chunk.
-  optional double budget_amount = 1;
+  optional double amount = 1;
 
   // The timestamp when the budget expires. Format is double to integrate with
   // Site Engagement and Blink and is the number of seconds since Jan 1, 1970.
-  optional double expiration_timestamp = 2;
+  optional double expiration = 2;
 }