[Offline pages] Adding capability to free up space used by Offline pages

components/offline_pages/offline_page_model.cc

Index: components/offline_pages/offline_page_model.cc
diff --git a/components/offline_pages/offline_page_model.cc b/components/offline_pages/offline_page_model.cc
index e89ae2add15ad730c64a7120bfad6fc60eb214cc..35e47f1e1f40d1fbfbd745154dba58647832e1aa 100644
--- a/components/offline_pages/offline_page_model.cc
+++ b/components/offline_pages/offline_page_model.cc
@@ -22,6 +22,10 @@ namespace offline_pages {
 
 namespace {
 
+// Threshold for how old offline copy of a page should be before we offer to
+// delete it to free up space.
+const base::TimeDelta kPageCleanUpThreshold = base::TimeDelta::FromDays(30);
+
 SavePageResult ToSavePageResult(ArchiverResult archiver_result) {
   SavePageResult result;
   switch (archiver_result) {
@@ -141,6 +145,17 @@ const std::vector<OfflinePageItem> OfflinePageModel::GetAllPages() const {
   return offline_pages;
 }
 
+const std::vector<OfflinePageItem> OfflinePageModel::GetPagesToCleanUp() const {
+  DCHECK(is_loaded_);
+  std::vector<OfflinePageItem> offline_pages;
+  base::Time now = base::Time::Now();
+  for (const auto& id_page_pair : offline_pages_) {
+    if (now - id_page_pair.second.creation_time > kPageCleanUpThreshold)
+      offline_pages.push_back(id_page_pair.second);
+  }
+  return offline_pages;
+}
+
 bool OfflinePageModel::GetPageByBookmarkId(
     int64 bookmark_id,
     OfflinePageItem* offline_page) const {