base: Remove non-const refs from the MRUCache implementation.

components/dom_distiller/core/distilled_content_store.cc

 // Copyright 2014 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 "components/dom_distiller/core/distilled_content_store.h"
 
 #include "base/message_loop/message_loop.h"
 
 namespace dom_distiller {
 
@@ skipping 78 matching lines @@
 }
 
 InMemoryContentStore::CacheDeletor::CacheDeletor(InMemoryContentStore* store)
     : store_(store) {
 }
 
 InMemoryContentStore::CacheDeletor::~CacheDeletor() {
 }
 
 void InMemoryContentStore::CacheDeletor::operator()(
-    const DistilledArticleProto& proto) {
+    DistilledArticleProto* proto) {
   // When InMemoryContentStore is deleted, the |store_| pointer becomes invalid,
   // but since the ContentMap is cleared in the InMemoryContentStore destructor,
   // this should never be called after the destructor.
-  store_->EraseUrlToIdMapping(proto);
+  store_->EraseUrlToIdMapping(*proto);
 }
 
 }  // namespace dom_distiller