Introduce all the plumbing for Session Storage. This mostly consists of crea...

chrome/renderer/renderer_webstoragenamespace_impl.cc

 // Copyright (c) 2009 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 "chrome/renderer/renderer_webstoragenamespace_impl.h"
 
 #include "chrome/common/render_messages.h"
 #include "chrome/renderer/render_thread.h"
 #include "chrome/renderer/renderer_webstoragearea_impl.h"
 
 using WebKit::WebStorageArea;
 using WebKit::WebStorageNamespace;
 using WebKit::WebString;
 
 RendererWebStorageNamespaceImpl::RendererWebStorageNamespaceImpl(
     DOMStorageType storage_type)
     : storage_type_(storage_type),
-      namespace_id_(kUninitializedNamespaceId) {
+      namespace_id_(kLocalStorageNamespaceId) {
+  DCHECK(storage_type == DOM_STORAGE_LOCAL);
 }
 
 RendererWebStorageNamespaceImpl::RendererWebStorageNamespaceImpl(
     DOMStorageType storage_type, int64 namespace_id)
     : storage_type_(storage_type),
       namespace_id_(namespace_id) {
-  DCHECK(namespace_id_ != kUninitializedNamespaceId);
+  DCHECK(storage_type == DOM_STORAGE_SESSION);
 }
 
 RendererWebStorageNamespaceImpl::~RendererWebStorageNamespaceImpl() {
 }
 
 WebStorageArea* RendererWebStorageNamespaceImpl::createStorageArea(
     const WebString& origin) {
-  // This could be done async in the background (started when this class is
-  // first instantiated) rather than lazily on first use, but it's unclear
-  // whether it's worth the complexity.
-  if (namespace_id_ == kUninitializedNamespaceId) {
-    RenderThread::current()->Send(
-        new ViewHostMsg_DOMStorageNamespaceId(storage_type_,
-                                              &namespace_id_));
-    DCHECK(namespace_id_ != kUninitializedNamespaceId);
-  }
   // Ideally, we'd keep a hash map of origin to these objects.  Unfortunately
   // this doesn't seem practical because there's no good way to ref-count these
-  // objects, and it'd be unclear who owned them.  So, instead, we'll pay a
-  // price for an allocaiton and IPC for each.
+  // objects, and it'd be unclear who owned them.  So, instead, we'll pay the
+  // price in terms of wasted memory.
   return new RendererWebStorageAreaImpl(namespace_id_, origin);
 }
 
 WebStorageNamespace* RendererWebStorageNamespaceImpl::copy() {
-  // If we haven't been used yet, we might as well start out fresh (and lazy).
-  if (namespace_id_ == kUninitializedNamespaceId)
-    return new RendererWebStorageNamespaceImpl(storage_type_);
-
-  // This cannot easily be deferred because we need a snapshot in time.
-  int64 new_namespace_id;
-  RenderThread::current()->Send(
-      new ViewHostMsg_DOMStorageCloneNamespaceId(namespace_id_,
-                                                 &new_namespace_id));
-  return new RendererWebStorageNamespaceImpl(storage_type_,
-                                             new_namespace_id);
+  NOTREACHED();  // We shouldn't ever reach this code in Chromium.
+  return NULL;
 }
 
 void RendererWebStorageNamespaceImpl::close() {
   // This is called only on LocalStorage namespaces when WebKit thinks its
   // shutting down.  This has no impact on Chromium.
 }