Add daily quota for precache

components/precache/core/proto/precache.proto

Index: components/precache/core/proto/precache.proto
diff --git a/components/precache/core/proto/precache.proto b/components/precache/core/proto/precache.proto
index b6be9b5a2bc5cebca1a1f10b7895737e4b473ba6..ae82ee6c286903db3d5ea7f740f40ca80ffeec93 100644
--- a/components/precache/core/proto/precache.proto
+++ b/components/precache/core/proto/precache.proto
@@ -84,4 +84,9 @@ message PrecacheConfigurationSettings {
   // downloads as well as cached resources. After this limit is reached, no
   // other resources will be downloaded.
   optional uint64 max_bytes_total = 5 [default = 10000000 /* 10 MB */];
+
+  // The maximum number of bytes that can be fetched by precache on a single
+  // day. After this limit is reached, no more resources will be downloaded,
+  // until the quota gets replenished the next day.
+  optional uint64 daily_quota_total = 6 [default = 10000000 /* 10 MB */];
 };