Add onChanged callback for chrome.sessions API.

chrome/browser/extensions/api/sessions/sessions_api.cc

Index: chrome/browser/extensions/api/sessions/sessions_api.cc
diff --git a/chrome/browser/extensions/api/sessions/sessions_api.cc b/chrome/browser/extensions/api/sessions/sessions_api.cc
index 52541b531028053f44ce1d450164459143d50973..8fdda8fb7032c0371fc107d8559db0d8b6d8b5e0 100644
--- a/chrome/browser/extensions/api/sessions/sessions_api.cc
+++ b/chrome/browser/extensions/api/sessions/sessions_api.cc
@@ -35,6 +35,7 @@
 #include "content/public/browser/web_contents.h"
 #include "extensions/browser/extension_function_dispatcher.h"
 #include "extensions/browser/extension_function_registry.h"
+#include "extensions/browser/extension_system.h"
 #include "extensions/common/error_utils.h"
 #include "net/base/net_util.h"
 #include "ui/base/layout.h"
@@ -584,4 +585,62 @@ bool SessionsRestoreFunction::RunImpl() {
       : RestoreLocalSession(*session_id, browser);
 }
 
+SessionsEventRouter::SessionsEventRouter(Profile* profile)
+    : profile_(profile),
+      tab_restore_service_(TabRestoreServiceFactory::GetForProfile(profile)) {
+  // TabRestoreServiceFactory::GetForProfile() can return NULL (i.e., when in
+  // incognito mode)
+  if (tab_restore_service_) {
+    tab_restore_service_->LoadTabsFromLastSession();
+    tab_restore_service_->AddObserver(this);
+  }
+}
+
+SessionsEventRouter::~SessionsEventRouter() {
+  if (tab_restore_service_)
+    tab_restore_service_->RemoveObserver(this);
+}
+
+void SessionsEventRouter::TabRestoreServiceChanged(
+    TabRestoreService* service) {
+  scoped_ptr<base::ListValue> args(new base::ListValue());
+  ExtensionSystem::Get(profile_)->event_router()->BroadcastEvent(

[not at google - send to devlin, 2014/03/26 21:12:38]

You can now use just EventRouter::Get(profile_) here and everywhere.

+      make_scoped_ptr(
+          new Event(api::sessions::OnChanged::kEventName, args.Pass())));
+}
+
+void SessionsEventRouter::TabRestoreServiceDestroyed(
+    TabRestoreService* service) {
+  tab_restore_service_ = NULL;
+}
+
+SessionsAPI::SessionsAPI(content::BrowserContext* context)
+    : browser_context_(context) {
+  ExtensionSystem::Get(browser_context_)->event_router()->RegisterObserver(
+      this, api::sessions::OnChanged::kEventName);
+}
+
+SessionsAPI::~SessionsAPI() {
+}
+
+void SessionsAPI::Shutdown() {
+  ExtensionSystem::Get(browser_context_)->event_router()->UnregisterObserver(
+      this);
+}
+
+static base::LazyInstance<BrowserContextKeyedAPIFactory<SessionsAPI> >
+    g_factory = LAZY_INSTANCE_INITIALIZER;
+
+BrowserContextKeyedAPIFactory<SessionsAPI>*
+SessionsAPI::GetFactoryInstance() {
+  return g_factory.Pointer();
+}
+
+void SessionsAPI::OnListenerAdded(const EventListenerInfo& details) {
+  sessions_event_router_.reset(
+      new SessionsEventRouter(Profile::FromBrowserContext(browser_context_)));
+  ExtensionSystem::Get(browser_context_)->event_router()->UnregisterObserver(
+      this);
+}
+
 }  // namespace extensions