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

content/browser/dom_storage/dom_storage_message_filter.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/dom_storage/dom_storage_message_filter.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/nullable_string16.h"
 #include "base/threading/sequenced_worker_pool.h"
@@ skipping 107 matching lines @@
   Send(new DOMStorageMsg_AsyncOperationComplete(true));
 }
 
 void DOMStorageMessageFilter::OnSetItem(
     int connection_id, const string16& key,
     const string16& value, const GURL& page_url) {
   DCHECK(!BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK_EQ(0, connection_dispatching_message_for_);
   base::AutoReset<int> auto_reset(&connection_dispatching_message_for_,
                             connection_id);
+  if (!context_->CanSetItem(host_.get(), connection_id, key, value)) {
+    Send(new DOMStorageMsg_AsyncOperationComplete(false));
+    return;
+  }

[Mike West, 2013/03/06 13:41:11]

This would likely be fairly easy to move to DomStorageHost, as michaeln
suggested on the other patch.

   NullableString16 not_used;
   bool success = host_->SetAreaItem(connection_id, key, value,
                                     page_url, &not_used);
   Send(new DOMStorageMsg_AsyncOperationComplete(success));
 }
 
 void DOMStorageMessageFilter::OnRemoveItem(
     int connection_id, const string16& key,
     const GURL& page_url) {
   DCHECK(!BrowserThread::CurrentlyOn(BrowserThread::IO));
@@ skipping 68 matching lines @@
     params.connection_id = connection_dispatching_message_for_;
     params.key = key;
     params.new_value = new_value;
     params.old_value = old_value;
     params.namespace_id = area->namespace_id();
     Send(new DOMStorageMsg_Event(params));
   }
 }
 
 }  // namespace content