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

content/renderer/dom_storage/dom_storage_dispatcher.cc

Index: content/renderer/dom_storage/dom_storage_dispatcher.cc
diff --git a/content/renderer/dom_storage/dom_storage_dispatcher.cc b/content/renderer/dom_storage/dom_storage_dispatcher.cc
index 5963694377729c2f912f6df5f077fd6005ebe142..ce942c963b5e83a15b3551273031477d62ded60e 100644
--- a/content/renderer/dom_storage/dom_storage_dispatcher.cc
+++ b/content/renderer/dom_storage/dom_storage_dispatcher.cc
@@ -13,6 +13,7 @@
 #include "content/renderer/dom_storage/webstoragearea_impl.h"
 #include "content/renderer/dom_storage/webstoragenamespace_impl.h"
 #include "content/renderer/render_thread_impl.h"
+#include "ipc/ipc_sync_message_filter.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/Platform.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebKit.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebStorageEventDispatcher.h"
@@ -103,7 +104,7 @@ class DomStorageDispatcher::ProxyImpl : public DomStorageProxy {
 
   // Methods for use by DomStorageDispatcher directly.
   DomStorageCachedArea* OpenCachedArea(
-      int64 namespace_id, const GURL& origin);
+      int64 namespace_id, const GURL& origin, int64 storage_size);
   void CloseCachedArea(DomStorageCachedArea* area);
   DomStorageCachedArea* LookupCachedArea(
       int64 namespace_id, const GURL& origin);
@@ -179,14 +180,14 @@ DomStorageDispatcher::ProxyImpl::ProxyImpl(RenderThreadImpl* sender)
 }
 
 DomStorageCachedArea* DomStorageDispatcher::ProxyImpl::OpenCachedArea(
-    int64 namespace_id, const GURL& origin) {
+    int64 namespace_id, const GURL& origin, int64 storage_size) {
   std::string key = GetCachedAreaKey(namespace_id, origin);
   if (CachedAreaHolder* holder = GetAreaHolder(key)) {
     ++(holder->open_count_);
     return holder->area_;
   }
   scoped_refptr<DomStorageCachedArea> area =
-      new DomStorageCachedArea(namespace_id, origin, this);
+      new DomStorageCachedArea(namespace_id, origin, this, storage_size);
   cached_areas_[key] = CachedAreaHolder(area, 1);
   return area.get();
 }
@@ -269,10 +270,17 @@ DomStorageDispatcher::~DomStorageDispatcher() {
 
 scoped_refptr<DomStorageCachedArea> DomStorageDispatcher::OpenCachedArea(
     int connection_id, int64 namespace_id, const GURL& origin) {
+  /*
   RenderThreadImpl::current()->Send(
       new DOMStorageHostMsg_OpenStorageArea(
           connection_id, namespace_id, origin));
-  return proxy_->OpenCachedArea(namespace_id, origin);
+          */
+  scoped_refptr<IPC::SyncMessageFilter> sync_msg_filter(
+      RenderThreadImpl::current()->sync_message_filter());
+  int64 storage_size = 0;
+  sync_msg_filter->Send(new DOMStorageHostMsg_OpenStorageArea(
+          connection_id, namespace_id, origin, &storage_size));
+  return proxy_->OpenCachedArea(namespace_id, origin, storage_size);
 }
 
 void DomStorageDispatcher::CloseCachedArea(
@@ -302,11 +310,15 @@ void DomStorageDispatcher::OnStorageEvent(
   if (originated_in_process) {
     originating_area = WebStorageAreaImpl::FromConnectionId(
         params.connection_id);
+    originating_area->cached_area()->set_global_storage_size(
+        params.storage_size);
   } else {
     DomStorageCachedArea* cached_area = proxy_->LookupCachedArea(
         params.namespace_id, params.origin);
-    if (cached_area)
+    if (cached_area) {
       cached_area->ApplyMutation(params.key, params.new_value);
+      cached_area->set_global_storage_size(params.storage_size);
+    }
   }
 
   if (params.namespace_id == dom_storage::kLocalStorageNamespaceId) {