[Sync] Avoid reinitializing server notifier client on XMPP reconnect

Will be unit-tested in a separate CL.

BUG=63857
TEST=Manual :(

Review URL: http://codereview.chromium.org/5293001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@67077 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 37 insertions, 35 deletions

diff --git a/chrome/browser/sync/notifier/chrome_invalidation_client.cc b/chrome/browser/sync/notifier/chrome_invalidation_client.cc
index 48cf3f4..0192371 100644
--- a/chrome/browser/sync/notifier/chrome_invalidation_client.cc
+++ b/chrome/browser/sync/notifier/chrome_invalidation_client.cc
@@ -38,7 +38,6 @@ void ChromeInvalidationClient::Start(
     Listener* listener, StateWriter* state_writer,
     base::WeakPtr<talk_base::Task> base_task) {
   DCHECK(non_thread_safe_.CalledOnValidThread());
-  DCHECK(base_task.get());
   Stop();
 
   chrome_system_resources_.StartScheduler();
@@ -64,14 +63,21 @@ void ChromeInvalidationClient::Start(
           &chrome_system_resources_, client_type, client_id, client_config,
           this));
   invalidation_client_->Start(state);
-  cache_invalidation_packet_handler_.reset(
-      new CacheInvalidationPacketHandler(base_task,
-                                         invalidation_client_.get()));
+  ChangeBaseTask(base_task);
   registration_manager_.reset(
       new RegistrationManager(invalidation_client_.get()));
   RegisterTypes();
 }
 
+void ChromeInvalidationClient::ChangeBaseTask(
+    base::WeakPtr<talk_base::Task> base_task) {
+  DCHECK(invalidation_client_.get());
+  DCHECK(base_task.get());
+  cache_invalidation_packet_handler_.reset(
+      new CacheInvalidationPacketHandler(base_task,
+                                         invalidation_client_.get()));
+}
+
 void ChromeInvalidationClient::Stop() {
   DCHECK(non_thread_safe_.CalledOnValidThread());
   if (!invalidation_client_.get()) {
diff --git a/chrome/browser/sync/notifier/chrome_invalidation_client.h b/chrome/browser/sync/notifier/chrome_invalidation_client.h
index 53e37f8..e6219f7 100644
--- a/chrome/browser/sync/notifier/chrome_invalidation_client.h
+++ b/chrome/browser/sync/notifier/chrome_invalidation_client.h
@@ -59,6 +59,11 @@ class ChromeInvalidationClient
 
   void Stop();
 
+  // Changes the task used to |base_task|, which must still be
+  // non-NULL.  Must only be called between calls to Start() and
+  // Stop().
+  void ChangeBaseTask(base::WeakPtr<talk_base::Task> base_task);
+
   // Register the sync types that we're interested in getting
   // notifications for.  Must only be called between calls to Start()
   // and Stop().
diff --git a/chrome/browser/sync/notifier/server_notifier_thread.cc b/chrome/browser/sync/notifier/server_notifier_thread.cc
index ede1a47..24a1c47 100644
--- a/chrome/browser/sync/notifier/server_notifier_thread.cc
+++ b/chrome/browser/sync/notifier/server_notifier_thread.cc
@@ -34,8 +34,7 @@ void ServerNotifierThread::ListenForUpdates() {
   DCHECK_EQ(MessageLoop::current(), parent_message_loop_);
   worker_message_loop()->PostTask(
       FROM_HERE,
-      NewRunnableMethod(this,
-                        &ServerNotifierThread::StartInvalidationListener));
+      NewRunnableMethod(this, &ServerNotifierThread::DoListenForUpdates));
 }
 
 void ServerNotifierThread::SubscribeForUpdates(
@@ -97,38 +96,34 @@ void ServerNotifierThread::WriteState(const std::string& state) {
   state_writers_->Notify(&StateWriter::WriteState, state);
 }
 
-void ServerNotifierThread::OnDisconnect() {
-  DCHECK_EQ(MessageLoop::current(), worker_message_loop());
-  StopInvalidationListener();
-  MediatorThreadImpl::OnDisconnect();
-}
-
-void ServerNotifierThread::StartInvalidationListener() {
+void ServerNotifierThread::DoListenForUpdates() {
   DCHECK_EQ(MessageLoop::current(), worker_message_loop());
   if (!base_task_.get()) {
     return;
   }
 
-  StopInvalidationListener();
-  chrome_invalidation_client_.reset(new ChromeInvalidationClient());
-
-  // TODO(akalin): Make cache_guid() part of the client ID.  If we do
-  // so and we somehow propagate it up to the server somehow, we can
-  // make it so that we won't receive any notifications that were
-  // generated from our own changes.
-  const std::string kClientId = "server_notifier_thread";
-  chrome_invalidation_client_->Start(
-      kClientId, state_, this, this, base_task_);
-  state_.clear();
+  if (chrome_invalidation_client_.get()) {
+    // If we already have an invalidation client, simply change the
+    // base task.
+    chrome_invalidation_client_->ChangeBaseTask(base_task_);
+  } else {
+    // Otherwise, create the invalidation client.
+    chrome_invalidation_client_.reset(new ChromeInvalidationClient());
+
+    // TODO(akalin): Make cache_guid() part of the client ID.  If we do
+    // so and we somehow propagate it up to the server somehow, we can
+    // make it so that we won't receive any notifications that were
+    // generated from our own changes.
+    const std::string kClientId = "server_notifier_thread";
+    chrome_invalidation_client_->Start(
+        kClientId, state_, this, this, base_task_);
+    state_.clear();
+  }
 }
 
 void ServerNotifierThread::RegisterTypesAndSignalSubscribed() {
   DCHECK_EQ(MessageLoop::current(), worker_message_loop());
-  // |chrome_invalidation_client_| can be NULL if we receive an
-  // OnDisconnect() event after we gets posted but before we run.
-  if (!chrome_invalidation_client_.get()) {
-    return;
-  }
+  DCHECK(chrome_invalidation_client_.get());
   chrome_invalidation_client_->RegisterTypes();
   observers_->Notify(&Observer::OnSubscriptionStateChange, true);
 }
diff --git a/chrome/browser/sync/notifier/server_notifier_thread.h b/chrome/browser/sync/notifier/server_notifier_thread.h
index 76ec4f1..55b60fe 100644
--- a/chrome/browser/sync/notifier/server_notifier_thread.h
+++ b/chrome/browser/sync/notifier/server_notifier_thread.h
@@ -65,18 +65,14 @@ class ServerNotifierThread
   // StateWriter implementation.
   virtual void WriteState(const std::string& state);
 
- protected:
-  virtual void OnDisconnect();
-
  private:
   // Posted to the worker thread by ListenForUpdates().
-  void StartInvalidationListener();
+  void DoListenForUpdates();
 
   // Posted to the worker thread by SubscribeForUpdates().
   void RegisterTypesAndSignalSubscribed();
 
-  // Called by StartInvalidationListener() and posted to the worker
-  // thread by Stop().
+  // Posted to the worker thread by Logout().
   void StopInvalidationListener();
 
   std::string state_;