[Sync] Convert SyncSessionSnapshot to a copy-able class.

sync/internal_api/js_sync_manager_observer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "sync/internal_api/js_sync_manager_observer.h"
 
 #include <cstddef>
 
 #include "base/location.h"
 #include "base/logging.h"
@@ skipping 13 matching lines @@
 JsSyncManagerObserver::JsSyncManagerObserver() {}
 
 JsSyncManagerObserver::~JsSyncManagerObserver() {}
 
 void JsSyncManagerObserver::SetJsEventHandler(
     const WeakHandle<JsEventHandler>& event_handler) {
   event_handler_ = event_handler;
 }
 
 void JsSyncManagerObserver::OnSyncCycleCompleted(
-    const sessions::SyncSessionSnapshot* snapshot) {
+    const sessions::SyncSessionSnapshot& snapshot) {
   if (!event_handler_.IsInitialized()) {
     return;
   }
   DictionaryValue details;
-  details.Set("snapshot", snapshot->ToValue());
+  details.Set("snapshot", snapshot.ToValue());
   HandleJsEvent(FROM_HERE, "onSyncCycleCompleted", JsEventDetails(&details));
 }
 
 void JsSyncManagerObserver::OnConnectionStatusChange(
     sync_api::ConnectionStatus status) {
   if (!event_handler_.IsInitialized()) {
     return;
   }
   DictionaryValue details;
   details.SetString("status", sync_api::ConnectionStatusToString(status));
@@ skipping 110 matching lines @@
     const std::string& name, const JsEventDetails& details) {
   if (!event_handler_.IsInitialized()) {
     NOTREACHED();
     return;
   }
   event_handler_.Call(from_here,
                       &JsEventHandler::HandleJsEvent, name, details);
 }
 
 }  // namespace browser_sync