Send the list of used and unused resources for precache

components/precache/core/proto/unfinished_work.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";
 
 import "precache.proto";
 
 package precache;
 
 // Chrome requires this.
 option optimize_for = LITE_RUNTIME;
 
 message TopHost {
   // The host name of a top host.
   optional string hostname = 1;
 };
 
-message PrecacheManifestURL {
+message DeprecatedPrecacheManifestURL {
   // The URL that provides a manifest.
   optional string url = 1;
 };
 
 // Information about the precache work that needs to be completed.
 message PrecacheUnfinishedWork {
   // Top hosts for which to fetch manifests.
   repeated TopHost top_host = 1;
 
   optional PrecacheConfigurationSettings config_settings = 2;
 
-  // Manifest URLs remaining to be fetched.
-  repeated PrecacheManifestURL manifest = 3;
+  // DEPRECATED: Manifest URLs remaining to be fetched.

[sclittle, 2016/08/16 21:05:06]

nit: While this is the normal way to deprecate things in a proto, I'd recommend
removing it completely, or commenting out these lines entirely. That way, the
compiler won't generate getters and setters for it, leading to a smaller binary
size.

Same thing with the DeprecatedPrecacheManifestURL message above.

[Raj, 2016/08/18 00:23:24]

Yes. Makes sense.

+  repeated DeprecatedPrecacheManifestURL deprecated_manifest = 3
+      [deprecated = true];
 
   // Resource URLs remaining to be fetched.
   repeated PrecacheResource resource = 4;
 
   // Tally of the total number of bytes contained in URL fetches, including
   // config, manifests, and resources. This the number of bytes as they would be
   // compressed over the network.
   optional uint64 total_bytes = 5;
 
   // Tally of the total number of bytes received over the network from URL
   // fetches (the same ones as in total_response_bytes_). This includes response
   // headers and intermediate responses such as 30xs.
   optional uint64 network_bytes = 6;
 
   // The total number of manifest URLs that the precache session started with.
   optional uint64 num_manifest_urls = 7;
 
   // The internal value of a base::Time object representing the precache
   // session start time. The start time is the time just before when top hosts
   // are requested.
   optional int64 start_time = 8;
 };