[Sync] Refactoring polling to be reliable.

chrome/browser/sync/glue/sync_backend_host_impl.cc

 // Copyright 2013 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 "chrome/browser/sync/glue/sync_backend_host_impl.h"
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/profiler/scoped_tracker.h"
 #include "chrome/browser/browser_process.h"
@@ skipping 169 matching lines @@
 }
 
 void SyncBackendHostImpl::StartSyncingWithServer() {
   SDVLOG(1) << "SyncBackendHostImpl::StartSyncingWithServer called.";
 
   syncer::ModelSafeRoutingInfo routing_info;
   registrar_->GetModelSafeRoutingInfo(&routing_info);
 
   registrar_->sync_thread()->message_loop()->PostTask(FROM_HERE,
       base::Bind(&SyncBackendHostCore::DoStartSyncing,
-                 core_.get(), routing_info));
+                 core_.get(), routing_info, sync_prefs_->GetLastPollTime()));
 }
 
 void SyncBackendHostImpl::SetEncryptionPassphrase(const std::string& passphrase,
                                                   bool is_explicit) {
   DCHECK(registrar_->sync_thread()->IsRunning());
   if (!IsNigoriEnabled()) {
     NOTREACHED() << "SetEncryptionPassphrase must never be called when nigori"
                     " is disabled.";
     return;
   }
@@ skipping 511 matching lines @@
 void SyncBackendHostImpl::HandleSyncCycleCompletedOnFrontendLoop(
     const syncer::sessions::SyncSessionSnapshot& snapshot) {
   if (!frontend_)
     return;
   DCHECK_EQ(base::MessageLoop::current(), frontend_loop_);
 
   last_snapshot_ = snapshot;
 
   SDVLOG(1) << "Got snapshot " << snapshot.ToString();
 
+  if (!snapshot.poll_finish_time().is_null())
+    sync_prefs_->SetLastPollTime(snapshot.poll_finish_time());
+
   // Process any changes to the datatypes we're syncing.
   // TODO(sync): add support for removing types.
   if (initialized())
     AddExperimentalTypes();
 
   if (initialized())
     frontend_->OnSyncCycleCompleted();
 }
 
 void SyncBackendHostImpl::RetryConfigurationOnFrontendLoop(
@@ skipping 163 matching lines @@
 
 base::MessageLoop* SyncBackendHostImpl::GetSyncLoopForTesting() {
   return registrar_->sync_thread()->message_loop();
 }
 
 }  // namespace browser_sync
 
 #undef SDVLOG
 
 #undef SLOG