sync: Remove ModelNeutralExecuteImpl()

ProcessUpdatesCommand was the only child of ModelChangingSyncerCommand
to override this function.  Since it is special, let's just treat it
specially in syncer.cc rather than modifying ModelChangingSyncerCommand
to suit its needs.

BUG=36594
TEST=


Review URL: http://codereview.chromium.org/8510079

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@110555 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/sync/engine/model_changing_syncer_command.cc

@@ -15,9 +15,6 @@ namespace browser_sync {
 
 void ModelChangingSyncerCommand::ExecuteImpl(sessions::SyncSession* session) {
   work_session_ = session;
-  if (!ModelNeutralExecuteImpl(work_session_)) {
-    return;
-  }
 
   // Project the list of active types (i.e., types in the routing
   // info) to a list of groups.
@@ -59,9 +56,4 @@ void ModelChangingSyncerCommand::ExecuteImpl(sessions::SyncSession* session) {
   }
 }
 
-bool ModelChangingSyncerCommand::ModelNeutralExecuteImpl(
-    sessions::SyncSession* session) {
-  return true;
-}
-
 }  // namespace browser_sync

chrome/browser/sync/engine/model_changing_syncer_command.h

@@ -40,14 +40,6 @@ class ModelChangingSyncerCommand : public SyncerCommand {
     return UnrecoverableErrorInfo();
   }
 
-  // Sometimes, a command has work to do that needs to touch global state
-  // belonging to multiple ModelSafeGroups, but in a way that is known to be
-  // safe.  This will be called once, prior to ModelChangingExecuteImpl,
-  // *without* a ModelSafeGroup restriction in place on the SyncSession.
-  // Returns true on success, false on failure.
-  // TODO(tim): Remove this (bug 36594).
-  virtual bool ModelNeutralExecuteImpl(sessions::SyncSession* session);
-
   // Abstract method to be implemented by subclasses to handle logic that
   // operates on the model.  This is invoked with a SyncSession ModelSafeGroup
   // restriction in place so that bits of state belonging to data types

chrome/browser/sync/engine/process_updates_command.cc

@@ -26,15 +26,6 @@ using sessions::StatusController;
 ProcessUpdatesCommand::ProcessUpdatesCommand() {}
 ProcessUpdatesCommand::~ProcessUpdatesCommand() {}
 
-bool ProcessUpdatesCommand::ModelNeutralExecuteImpl(SyncSession* session) {
-  const GetUpdatesResponse& updates =
-      session->status_controller()->updates_response().get_updates();
-  const int update_count = updates.entries_size();
-
-  // Don't bother processing updates if there were none.
-  return update_count != 0;
-}
-
 void ProcessUpdatesCommand::ModelChangingExecuteImpl(SyncSession* session) {
   syncable::ScopedDirLookup dir(session->context()->directory_manager(),
                                 session->context()->account_name());

chrome/browser/sync/engine/process_updates_command.h

@@ -34,7 +34,6 @@ class ProcessUpdatesCommand : public ModelChangingSyncerCommand {
   virtual ~ProcessUpdatesCommand();
 
   // ModelChangingSyncerCommand implementation.
-  virtual bool ModelNeutralExecuteImpl(sessions::SyncSession* session);
   virtual void ModelChangingExecuteImpl(sessions::SyncSession* session);
 
  private:

chrome/browser/sync/engine/syncer.cc

@@ -143,8 +143,10 @@ void Syncer::SyncShare(sessions::SyncSession* session,
       }
       case PROCESS_UPDATES: {
         VLOG(1) << "Processing Updates";
-        ProcessUpdatesCommand process_updates;
-        process_updates.Execute(session);
+        if (session->status_controller()->ResponseContainsUpdates()) {
+          ProcessUpdatesCommand process_updates;
+          process_updates.Execute(session);
+        }
         next_step = STORE_TIMESTAMPS;
         break;
       }

chrome/browser/sync/sessions/status_controller.cc

@@ -242,6 +242,10 @@ bool StatusController::ServerSaysNothingMoreToDownload() const {
   return updates_response().get_updates().changes_remaining() == 0;
 }
 
+bool StatusController::ResponseContainsUpdates() const {
+  return updates_response().get_updates().entries_size() != 0;
+}
+
 void StatusController::set_debug_info_sent() {
   shared_.control_params.debug_info_sent = true;
 }

chrome/browser/sync/sessions/status_controller.h

@@ -189,6 +189,9 @@ class StatusController {
   // download: in that case, this also returns false.
   bool ServerSaysNothingMoreToDownload() const;
 
+  // Returns true if there are updates to be processed.
+  bool ResponseContainsUpdates() const;
+
   ModelSafeGroup group_restriction() const {
     return group_restriction_;
   }