First half of http://codereview.chromium.org/274014/show...

chrome/browser/in_process_webkit/dom_storage_dispatcher_host.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/browser/in_process_webkit/dom_storage_dispatcher_host.h"
 
 #include "base/nullable_string16.h"
 #include "chrome/browser/chrome_thread.h"
 #include "chrome/browser/in_process_webkit/dom_storage_context.h"
 #include "chrome/browser/in_process_webkit/storage_area.h"
 #include "chrome/browser/in_process_webkit/storage_namespace.h"
 #include "chrome/browser/in_process_webkit/webkit_thread.h"
 #include "chrome/browser/renderer_host/browser_render_process_host.h"
 #include "chrome/common/render_messages.h"
 
-DOMStorageDispatcherHost* DOMStorageDispatcherHost::current_ = NULL;
+DOMStorageDispatcherHost* DOMStorageDispatcherHost::storage_event_host_ = NULL;
 
 DOMStorageDispatcherHost::
-AutoSetCurrentDispatcherHost::AutoSetCurrentDispatcherHost(
+ScopedStorageEventContext::ScopedStorageEventContext(
     DOMStorageDispatcherHost* dispatcher_host) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::WEBKIT));
-  DCHECK(!current_);
-  current_ = dispatcher_host;
+  DCHECK(!storage_event_host_);
+  storage_event_host_ = dispatcher_host;
+  DCHECK(storage_event_host_);
 }
 
 DOMStorageDispatcherHost::
-AutoSetCurrentDispatcherHost::~AutoSetCurrentDispatcherHost() {
+ScopedStorageEventContext::~ScopedStorageEventContext() {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::WEBKIT));
-  DCHECK(current_);
-  current_ = NULL;
+  DCHECK(storage_event_host_);
+  storage_event_host_ = NULL;
 }
 
 DOMStorageDispatcherHost::DOMStorageDispatcherHost(
     IPC::Message::Sender* message_sender, WebKitContext* webkit_context,
     WebKitThread* webkit_thread)
     : webkit_context_(webkit_context),
       webkit_thread_(webkit_thread),
       message_sender_(message_sender),
       process_handle_(0) {
   DCHECK(webkit_context_.get());
@@ skipping 28 matching lines @@
 
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::WEBKIT));
   DCHECK(!message_sender_);
 
   // TODO(jorlow): Do stuff that needs to be run on the WebKit thread.  Locks
   //               and others will likely need this, so let's not delete this
   //               code even though it doesn't do anyting yet.
 }
 
 /* static */
-void DOMStorageDispatcherHost::DispatchStorageEvent(const string16& key,
+void DOMStorageDispatcherHost::DispatchStorageEvent(const NullableString16& key,
     const NullableString16& old_value, const NullableString16& new_value,
     const string16& origin, bool is_local_storage) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::WEBKIT));
-  DCHECK(current_);
-  ChromeThread::PostTask(
-      ChromeThread::IO, FROM_HERE,
-      NewRunnableMethod(
-          current_, &DOMStorageDispatcherHost::OnStorageEvent, key, old_value,
-          new_value, origin, is_local_storage));
+  DCHECK(is_local_storage);  // Only LocalStorage is implemented right now.
+  DCHECK(storage_event_host_);
+  ViewMsg_DOMStorageEvent_Params params;
+  params.key_ = key;
+  params.old_value_ = old_value;
+  params.new_value_ = new_value;
+  params.origin_ = origin;
+  params.storage_type_ = is_local_storage ? DOM_STORAGE_LOCAL
+                                          : DOM_STORAGE_SESSION;
+  // The storage_event_host_ is the DOMStorageDispatcherHost that is up in the
+  // current call stack since it caused the storage event to fire.
+  ChromeThread::PostTask(ChromeThread::IO, FROM_HERE,
+      NewRunnableMethod(storage_event_host_,
+          &DOMStorageDispatcherHost::OnStorageEvent, params));
 }
 
 bool DOMStorageDispatcherHost::OnMessageReceived(const IPC::Message& message,
                                                  bool *msg_is_ok) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
   DCHECK(process_handle_);
 
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP_EX(DOMStorageDispatcherHost, message, *msg_is_ok)
     IPC_MESSAGE_HANDLER_DELAY_REPLY(ViewHostMsg_DOMStorageNamespaceId,
@@ skipping 176 matching lines @@
 
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::WEBKIT));
   bool quota_exception = false;
   StorageArea* storage_area = Context()->GetStorageArea(storage_area_id);
   if (!storage_area) {
     BrowserRenderProcessHost::BadMessageTerminateProcess(
         ViewHostMsg_DOMStorageSetItem::ID, process_handle_);
     return;
   }
 
-  AutoSetCurrentDispatcherHost auto_set(this);
+  ScopedStorageEventContext scope(this);
   storage_area->SetItem(key, value, &quota_exception);
   ViewHostMsg_DOMStorageSetItem::WriteReplyParams(reply_msg, quota_exception);
   Send(reply_msg);
 }
 
-void DOMStorageDispatcherHost::OnRemoveItem(int64 storage_area_id,
-                                            const string16& key) {
+void DOMStorageDispatcherHost::OnRemoveItem(
+    int64 storage_area_id, const string16& key) {
   if (ChromeThread::CurrentlyOn(ChromeThread::IO)) {
     PostTaskToWebKitThread(FROM_HERE, NewRunnableMethod(this,
         &DOMStorageDispatcherHost::OnRemoveItem, storage_area_id, key));
     return;
   }
 
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::WEBKIT));
   StorageArea* storage_area = Context()->GetStorageArea(storage_area_id);
   if (!storage_area) {
     BrowserRenderProcessHost::BadMessageTerminateProcess(
         ViewHostMsg_DOMStorageRemoveItem::ID, process_handle_);
     return;
   }
 
-  AutoSetCurrentDispatcherHost auto_set(this);
+  ScopedStorageEventContext scope(this);
   storage_area->RemoveItem(key);
 }
 
 void DOMStorageDispatcherHost::OnClear(int64 storage_area_id) {
   if (ChromeThread::CurrentlyOn(ChromeThread::IO)) {
     PostTaskToWebKitThread(FROM_HERE, NewRunnableMethod(this,
         &DOMStorageDispatcherHost::OnClear, storage_area_id));
     return;
   }
 
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::WEBKIT));
   StorageArea* storage_area = Context()->GetStorageArea(storage_area_id);
   if (!storage_area) {
     BrowserRenderProcessHost::BadMessageTerminateProcess(
         ViewHostMsg_DOMStorageClear::ID, process_handle_);
     return;
   }
 
-  AutoSetCurrentDispatcherHost auto_set(this);
+  ScopedStorageEventContext scope(this);
   storage_area->Clear();
 }
 
-void DOMStorageDispatcherHost::OnStorageEvent(const string16& key,
-    const NullableString16& old_value, const NullableString16& new_value,
-    const string16& origin, bool is_local_storage) {
+void DOMStorageDispatcherHost::OnStorageEvent(
+    const ViewMsg_DOMStorageEvent_Params& params) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
-  DCHECK(is_local_storage);  // Only LocalStorage is implemented right now.
-  DOMStorageType dom_storage_type = is_local_storage ? DOM_STORAGE_LOCAL
-                                                     : DOM_STORAGE_SESSION;
   const DOMStorageContext::DispatcherHostSet* set =
       Context()->GetDispatcherHostSet();
   DOMStorageContext::DispatcherHostSet::const_iterator cur = set->begin();
   while (cur != set->end()) {
-    (*cur)->Send(new ViewMsg_DOMStorageEvent(key, old_value, new_value, origin,
-                                             dom_storage_type));
+    (*cur)->Send(new ViewMsg_DOMStorageEvent(params));
     ++cur;
   }
 }
 
 void DOMStorageDispatcherHost::PostTaskToWebKitThread(
     const tracked_objects::Location& from_here, Task* task) {
   webkit_thread_->EnsureInitialized();
   ChromeThread::PostTask(ChromeThread::WEBKIT, FROM_HERE, task);
 }