[Offline Pages] Two-step expiration in storage manager.

components/offline_pages/offline_page_client_policy.h

Index: components/offline_pages/offline_page_client_policy.h
diff --git a/components/offline_pages/offline_page_client_policy.h b/components/offline_pages/offline_page_client_policy.h
index 8b47d3a1a31b4ff521c2e8dcf1ce9bc423a10f74..910b0ddae925f2000b6c34cef748219d3d859e48 100644
--- a/components/offline_pages/offline_page_client_policy.h
+++ b/components/offline_pages/offline_page_client_policy.h
@@ -13,7 +13,7 @@
 
 namespace offline_pages {
 
-static const int kUnlimitedPages = 0;
+static const size_t kUnlimitedPages = 0;
 
 // The struct describing the lifetime policy of offline pages.
 // The following behaviors are controlled by policy:
@@ -36,7 +36,7 @@ struct LifetimePolicy {
 
   // The maximum number of pages allowed to be saved by the namespace.
   // kUnlimitedPages (defined above) means no limit set.
-  int page_limit;
+  size_t page_limit;
 };
 
 // The struct describing policies for various namespaces (Bookmark, Last-N etc.)