Add daily quota for precache

components/precache/core/proto/quota.proto

Index: components/precache/core/proto/quota.proto
diff --git a/components/precache/core/proto/quota.proto b/components/precache/core/proto/quota.proto
new file mode 100644
index 0000000000000000000000000000000000000000..e557b0f4b9138f24e1928783c9c67c11852683ce
--- /dev/null
+++ b/components/precache/core/proto/quota.proto
@@ -0,0 +1,19 @@
+// Copyright 2013 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 precache;
+
+// Chrome requires this.
+option optimize_for = LITE_RUNTIME;
+
+// Quota limit and expiry time.

[sclittle, 2016/09/14 17:59:18]

nit: Could you also mention here that this is stored in a database, and not
transmitted anywhere?

[Raj, 2016/09/14 20:01:51]

Done.

+message PrecacheQuota {
+  // Represents the time of expiry of this quota.
+  optional int64 expiry_time = 1;
+
+  // Maximum number of bytes that can be fetched until this quota expires.
+  optional uint64 remaining = 2;
+};