Purge in-memory localStorage areas if the # of areas exceeds the limit

webkit/dom_storage/dom_storage_cached_area.cc

Index: webkit/dom_storage/dom_storage_cached_area.cc
diff --git a/webkit/dom_storage/dom_storage_cached_area.cc b/webkit/dom_storage/dom_storage_cached_area.cc
index 30d6291d32a5e184f9aa013b3f4a81b658b23a02..2e1ec2023ab0e9d4a92d46a6a94f91fe64539839 100644
--- a/webkit/dom_storage/dom_storage_cached_area.cc
+++ b/webkit/dom_storage/dom_storage_cached_area.cc
@@ -13,10 +13,12 @@
 namespace dom_storage {
 
 DomStorageCachedArea::DomStorageCachedArea(
-    int64 namespace_id, const GURL& origin, DomStorageProxy* proxy)
+    int64 namespace_id, const GURL& origin, DomStorageProxy* proxy,
+    int64 storage_size)
     : ignore_all_mutations_(false),
       namespace_id_(namespace_id), origin_(origin),
-      proxy_(proxy), weak_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)) {
+      proxy_(proxy), weak_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)),
+      global_storage_size_(storage_size) {
 }
 
 DomStorageCachedArea::~DomStorageCachedArea() {
@@ -47,6 +49,12 @@ bool DomStorageCachedArea::SetItem(
   if (key.length() + value.length() > dom_storage::kPerAreaQuota)
     return false;
 
+  // TENTATIVE: Limit the global data to 512MB.
+  if (key.length() + value.length() + global_storage_size_
+      > 512 * 1024 * 1024) {
+    return false;
+  }
+
   PrimeIfNeeded(connection_id);
   NullableString16 unused;
   if (!map_->SetItem(key, value, &unused))