Sync: Refactoring of DEVICE_INFO syncable type - Part 1

chrome/browser/sync/sessions/session_data_type_controller.cc

Index: chrome/browser/sync/sessions/session_data_type_controller.cc
diff --git a/chrome/browser/sync/sessions/session_data_type_controller.cc b/chrome/browser/sync/sessions/session_data_type_controller.cc
index 25578b633782bf2008e974d58bf050517b1536ee..1ae2c904c54c0ad5e842dbbf4890be03fdea5a8f 100644
--- a/chrome/browser/sync/sessions/session_data_type_controller.cc
+++ b/chrome/browser/sync/sessions/session_data_type_controller.cc
@@ -8,6 +8,7 @@
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sync/glue/chrome_report_unrecoverable_error.h"
 #include "chrome/browser/sync/glue/synced_window_delegate.h"
+#include "chrome/browser/sync/sessions/synced_window_delegates_getter.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_details.h"
 #include "content/public/browser/notification_service.h"
@@ -20,6 +21,8 @@ namespace browser_sync {
 SessionDataTypeController::SessionDataTypeController(
     SyncApiComponentFactory* sync_factory,
     Profile* profile,
+    SyncedWindowDelegatesGetter* synced_window_getter,
+    LocalDeviceInfoProvider* local_device,
     const DisableTypeCallback& disable_callback)
     : UIDataTypeController(
           BrowserThread::GetMessageLoopProxyForThread(BrowserThread::UI),
@@ -27,7 +30,12 @@ SessionDataTypeController::SessionDataTypeController(
           disable_callback,
           syncer::SESSIONS,
           sync_factory),
-      profile_(profile) {
+      profile_(profile),
+      synced_window_getter_(synced_window_getter),
+      local_device_(local_device),
+      waiting_on_session_restore_(false),
+      waiting_on_local_device_info_(false) {
+  DCHECK(local_device_);
 }
 
 SessionDataTypeController::~SessionDataTypeController() {}
@@ -35,7 +43,7 @@ SessionDataTypeController::~SessionDataTypeController() {}
 bool SessionDataTypeController::StartModels() {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   std::set<browser_sync::SyncedWindowDelegate*> window =
-      browser_sync::SyncedWindowDelegate::GetSyncedWindowDelegates();
+      synced_window_getter_->GetSyncedWindowDelegates();
   for (std::set<browser_sync::SyncedWindowDelegate*>::const_iterator i =
       window.begin(); i != window.end(); ++i) {
     if ((*i)->IsSessionRestoreInProgress()) {
@@ -43,16 +51,35 @@ bool SessionDataTypeController::StartModels() {
           this,
           chrome::NOTIFICATION_SESSION_RESTORE_COMPLETE,
           content::Source<Profile>(profile_));
-      return false;
+      waiting_on_session_restore_ = true;
+      break;
     }
   }
-  return true;
+
+  if (!local_device_->IsInitialized()) {

[rlarocque, 2014/07/08 18:25:38]

I like the way you've handled this, but I can't think of a scenario where this
can happen in practice.

Sync should never try to initialize the DataTypeController unless the backend is
initialized.  Once the backend is initialized, we should have a cache_guid
available.

[stanisc, 2014/07/09 21:58:37]

Local Device Info initialization is asynchronous. When backend is initialized we
get cache_guid and start local device info initialization but it isn't
immediately ready and becomes available a bit later.

+    subscription_ = local_device_->RegisterOnInitializedCallback(
+        base::Bind(&SessionDataTypeController::OnLocalDeviceInfoInitialized,
+                   this));
+    waiting_on_local_device_info_ = true;
+  }
+
+  return !IsWaiting();
 }
 
 void SessionDataTypeController::StopModels() {
   notification_registrar_.RemoveAll();
 }
 
+bool SessionDataTypeController::IsWaiting() {
+  return waiting_on_session_restore_ || waiting_on_local_device_info_;
+}
+
+void SessionDataTypeController::MaybeCompleteLoading() {
+  if (state_ == MODEL_STARTING && !IsWaiting()) {
+    OnModelLoaded();
+  }
+}
+
 void SessionDataTypeController::Observe(
     int type,
     const content::NotificationSource& source,
@@ -61,7 +88,17 @@ void SessionDataTypeController::Observe(
   DCHECK_EQ(chrome::NOTIFICATION_SESSION_RESTORE_COMPLETE, type);
   DCHECK_EQ(profile_, content::Source<Profile>(source).ptr());
   notification_registrar_.RemoveAll();
-  OnModelLoaded();
+
+  waiting_on_session_restore_ = false;
+  MaybeCompleteLoading();
+}
+
+void SessionDataTypeController::OnLocalDeviceInfoInitialized() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  subscription_.reset();
+
+  waiting_on_local_device_info_ = false;
+  MaybeCompleteLoading();
 }
 
 }  // namespace browser_sync