Another stab at the Chromium side of storage events. The WebKit side can be ...

chrome/browser/in_process_webkit/dom_storage_dispatcher_host.cc

Index: chrome/browser/in_process_webkit/dom_storage_dispatcher_host.cc
===================================================================
--- chrome/browser/in_process_webkit/dom_storage_dispatcher_host.cc	(revision 27652)
+++ chrome/browser/in_process_webkit/dom_storage_dispatcher_host.cc	(working copy)
@@ -13,6 +13,23 @@
 #include "chrome/browser/renderer_host/browser_render_process_host.h"
 #include "chrome/common/render_messages.h"
 
+DOMStorageDispatcherHost* DOMStorageDispatcherHost::current_ = NULL;
+
+DOMStorageDispatcherHost::
+AutoSetCurrentDispatcherHost::AutoSetCurrentDispatcherHost(
+    DOMStorageDispatcherHost* dispatcher_host) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::WEBKIT));
+  DCHECK(!current_);
+  current_ = dispatcher_host;
+}
+
+DOMStorageDispatcherHost::
+AutoSetCurrentDispatcherHost::~AutoSetCurrentDispatcherHost() {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::WEBKIT));
+  DCHECK(current_);
+  current_ = NULL;
+}
+
 DOMStorageDispatcherHost::DOMStorageDispatcherHost(
     IPC::Message::Sender* message_sender, WebKitContext* webkit_context,
     WebKitThread* webkit_thread)
@@ -32,6 +49,9 @@
 }
 
 void DOMStorageDispatcherHost::Init(base::ProcessHandle process_handle) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
+  Context()->RegisterDispatcherHost(this);
+
   DCHECK(!process_handle_);
   process_handle_ = process_handle;
   DCHECK(process_handle_);
@@ -39,6 +59,7 @@
 
 void DOMStorageDispatcherHost::Shutdown() {
   if (ChromeThread::CurrentlyOn(ChromeThread::IO)) {
+    Context()->UnregisterDispatcherHost(this);
     message_sender_ = NULL;
     if (!ever_used_) {
       // No need to (possibly) spin up the WebKit thread for a no-op.
@@ -58,12 +79,24 @@
   DCHECK(!shutdown_);
   shutdown_ = true;
 
-  // TODO(jorlow): If we have any locks or are tracking resources that need to
-  //               be released on the WebKit thread, do it here.
+  // 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.
 }
 
-bool DOMStorageDispatcherHost::OnMessageReceived(
-    const IPC::Message& message, bool *msg_is_ok) {
+/* static */
+void DOMStorageDispatcherHost::DispatchStorageEvent(const string16& key,
+    const NullableString16& old_value, const NullableString16& new_value,
+    const string16& origin, bool is_local_storage) {
+  DCHECK(ChromeThread::CurrentlyOn(ChromeThread::WEBKIT));
+  DCHECK(current_);
+  current_->webkit_thread_->PostIOThreadTask(FROM_HERE, NewRunnableMethod(
+        current_, &DOMStorageDispatcherHost::OnStorageEvent, key, old_value,
+        new_value, origin, is_local_storage));
+}
+
+bool DOMStorageDispatcherHost::OnMessageReceived(const IPC::Message& message,
+                                                 bool *msg_is_ok) {
   DCHECK(ChromeThread::CurrentlyOn(ChromeThread::IO));
   DCHECK(!shutdown_);
   DCHECK(process_handle_);
@@ -272,6 +305,8 @@
         ViewHostMsg_DOMStorageSetItem::ID, process_handle_);
     return;
   }
+
+  AutoSetCurrentDispatcherHost auto_set(this);
   storage_area->SetItem(key, value, &quota_exception);
   DCHECK(!quota_exception);  // This is tracked by the renderer.
 }
@@ -293,6 +328,8 @@
         ViewHostMsg_DOMStorageRemoveItem::ID, process_handle_);
     return;
   }
+
+  AutoSetCurrentDispatcherHost auto_set(this);
   storage_area->RemoveItem(key);
 }
 
@@ -312,5 +349,24 @@
         ViewHostMsg_DOMStorageClear::ID, process_handle_);
     return;
   }
+
+  AutoSetCurrentDispatcherHost auto_set(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) {
+  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;
+  }
+}