4 files changed, 44 insertions, 8 deletions
diff --git a/chrome/browser/sync/engine/syncapi.cc b/chrome/browser/sync/engine/syncapi.cc
index 433475c..e807d3d 100644
--- a/chrome/browser/sync/engine/syncapi.cc
+++ b/chrome/browser/sync/engine/syncapi.cc
@@ -1739,7 +1739,7 @@ void SyncManager::SyncInternal::HandleSyncerEvent(const SyncerEvent& event) {
   // whether we should sync again.
   if (event.what_happened == SyncerEvent::SYNC_CYCLE_ENDED) {
     if (!event.snapshot->has_more_to_sync) {
-      observer_->OnSyncCycleCompleted();
+      observer_->OnSyncCycleCompleted(event.snapshot);
     }
 
     // TODO(chron): Consider changing this back to track has_more_to_sync
diff --git a/chrome/browser/sync/engine/syncapi.h b/chrome/browser/sync/engine/syncapi.h
index ca1cc01..98aeeb9 100644
--- a/chrome/browser/sync/engine/syncapi.h
+++ b/chrome/browser/sync/engine/syncapi.h
@@ -53,6 +53,10 @@
 
 namespace browser_sync {
 class ModelSafeWorkerRegistrar;
+
+namespace sessions {
+struct SyncSessionSnapshot;
+}
 }
 
 // Forward declarations of internal class types so that sync API objects
@@ -564,10 +568,9 @@ class SyncManager {
                                   int change_count) = 0;
 
     // A round-trip sync-cycle took place and the syncer has resolved any
-    // conflicts that may have arisen.  This is kept separate from
-    // OnStatusChanged as there isn't really any state update; it is plainly
-    // a notification of a state transition.
-    virtual void OnSyncCycleCompleted() = 0;
+    // conflicts that may have arisen.
+    virtual void OnSyncCycleCompleted(
+        const browser_sync::sessions::SyncSessionSnapshot* snapshot) = 0;
 
     // Called when user interaction may be required due to an auth problem.
     virtual void OnAuthError(const GoogleServiceAuthError& auth_error) = 0;
diff --git a/chrome/browser/sync/glue/sync_backend_host.cc b/chrome/browser/sync/glue/sync_backend_host.cc
index 51a8f86..ae3519d 100644
--- a/chrome/browser/sync/glue/sync_backend_host.cc
+++ b/chrome/browser/sync/glue/sync_backend_host.cc
@@ -13,6 +13,7 @@
 #include "chrome/browser/sync/glue/history_model_worker.h"
 #include "chrome/browser/sync/glue/sync_backend_host.h"
 #include "chrome/browser/sync/glue/http_bridge.h"
+#include "chrome/browser/sync/sessions/session_state.h"
 #include "chrome/common/notification_service.h"
 #include "chrome/common/notification_type.h"
 #include "webkit/glue/webkit_glue.h"
@@ -29,6 +30,8 @@ typedef GoogleServiceAuthError AuthError;
 
 namespace browser_sync {
 
+using sessions::SyncSessionSnapshot;
+
 SyncBackendHost::SyncBackendHost(
     SyncFrontend* frontend,
     Profile* profile,
@@ -242,6 +245,10 @@ const GoogleServiceAuthError& SyncBackendHost::GetAuthError() const {
   return last_auth_error_;
 }
 
+const SyncSessionSnapshot* SyncBackendHost::GetLastSessionSnapshot() const {
+  return last_snapshot_.get();
+}
+
 void SyncBackendHost::GetWorkers(std::vector<ModelSafeWorker*>* out) {
   AutoLock lock(registrar_lock_);
   out->clear();
@@ -387,9 +394,21 @@ void SyncBackendHost::Core::OnChangesApplied(
   processor->ApplyChangesFromSyncModel(trans, changes, change_count);
 }
 
-void SyncBackendHost::Core::OnSyncCycleCompleted() {
+void SyncBackendHost::Core::OnSyncCycleCompleted(
+    const SyncSessionSnapshot* snapshot) {
   host_->frontend_loop_->PostTask(FROM_HERE, NewRunnableMethod(this,
-      &Core::NotifyFrontend, SYNC_CYCLE_COMPLETED));
+      &Core::HandleSyncCycleCompletedOnFrontendLoop,
+      new SyncSessionSnapshot(*snapshot)));
+}
+
+void SyncBackendHost::Core::HandleSyncCycleCompletedOnFrontendLoop(
+    SyncSessionSnapshot* snapshot) {
+  if (!host_ || !host_->frontend_)
+    return;
+  DCHECK_EQ(MessageLoop::current(), host_->frontend_loop_);
+
+  host_->last_snapshot_.reset(snapshot);
+  host_->frontend_->OnSyncCycleCompleted();
 }
 
 void SyncBackendHost::Core::OnInitializationComplete() {
diff --git a/chrome/browser/sync/glue/sync_backend_host.h b/chrome/browser/sync/glue/sync_backend_host.h
index 8edc7ba..e362d09 100644
--- a/chrome/browser/sync/glue/sync_backend_host.h
+++ b/chrome/browser/sync/glue/sync_backend_host.h
@@ -29,6 +29,10 @@ class Profile;
 
 namespace browser_sync {
 
+namespace sessions {
+struct SyncSessionSnapshot;
+}
+
 class ChangeProcessor;
 class DataTypeController;
 
@@ -135,6 +139,7 @@ class SyncBackendHost : public browser_sync::ModelSafeWorkerRegistrar {
   Status GetDetailedStatus();
   StatusSummary GetStatusSummary();
   const GoogleServiceAuthError& GetAuthError() const;
+  const sessions::SyncSessionSnapshot* GetLastSessionSnapshot() const;
 
   const FilePath& sync_data_folder_path() const {
     return sync_data_folder_path_;
@@ -191,7 +196,8 @@ class SyncBackendHost : public browser_sync::ModelSafeWorkerRegistrar {
         const sync_api::BaseTransaction* trans,
         const sync_api::SyncManager::ChangeRecord* changes,
         int change_count);
-    virtual void OnSyncCycleCompleted();
+    virtual void OnSyncCycleCompleted(
+        const sessions::SyncSessionSnapshot* snapshot);
     virtual void OnInitializationComplete();
     virtual void OnAuthError(const GoogleServiceAuthError& auth_error);
     virtual void OnPaused();
@@ -334,6 +340,11 @@ class SyncBackendHost : public browser_sync::ModelSafeWorkerRegistrar {
     void HandleAuthErrorEventOnFrontendLoop(
         const GoogleServiceAuthError& new_auth_error);
 
+    // Called from Core::OnSyncCycleCompleted to handle updating frontend
+    // thread components.
+    void HandleSyncCycleCompletedOnFrontendLoop(
+        sessions::SyncSessionSnapshot* snapshot);
+
     // Our parent SyncBackendHost
     SyncBackendHost* host_;
 
@@ -403,6 +414,9 @@ class SyncBackendHost : public browser_sync::ModelSafeWorkerRegistrar {
   // UI-thread cache of the last AuthErrorState received from syncapi.
   GoogleServiceAuthError last_auth_error_;
 
+  // UI-thread cache of the last SyncSessionSnapshot received from syncapi.
+  scoped_ptr<sessions::SyncSessionSnapshot> last_snapshot_;
+
   DISALLOW_COPY_AND_ASSIGN(SyncBackendHost);
 };