sync: Add GetAllSyncData to sync/api

chrome/browser/sync/glue/generic_change_processor.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 "chrome/browser/sync/glue/generic_change_processor.h"
 
 #include "base/location.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 120 matching lines @@
                                                        syncer_changes_);
   syncer_changes_.clear();
   if (error.IsSet()) {
     error_handler()->OnSingleDatatypeUnrecoverableError(
         error.location(), error.message());
   }
 }
 
 syncer::SyncError GenericChangeProcessor::GetSyncDataForType(
     syncer::ModelType type,
-    syncer::SyncDataList* current_sync_data) {
+    syncer::SyncDataList* current_sync_data) const {
   DCHECK(CalledOnValidThread());
   std::string type_name = syncer::ModelTypeToString(type);
   syncer::ReadTransaction trans(FROM_HERE, share_handle());
   syncer::ReadNode root(&trans);
   if (root.InitByTagLookup(syncer::ModelTypeToRootTag(type)) !=
           syncer::BaseNode::INIT_OK) {
     syncer::SyncError error(FROM_HERE,
                             syncer::SyncError::DATATYPE_ERROR,
                             "Server did not create the top-level " + type_name +
                                 " node. We might be running against an out-of-"
@@ skipping 144 matching lines @@
   }
   if (IsActOnceDataType(type))
     node->Drop();
   else
     node->Tombstone();
   return syncer::SyncError();
 }
 
 }  // namespace
 
+syncer::SyncDataList GenericChangeProcessor::GetAllSyncData(
+    syncer::ModelType type) const {
+  // This is slow / memory intensive.  Should be used sparingly by datatypes.
+  syncer::SyncDataList data;
+  if (GetSyncDataForType(type, &data).IsSet())
+    return syncer::SyncDataList();
+  return data;
+}
+
 // WARNING: this code is sensitive to compiler optimizations. Be careful
 // modifying any code around an OnSingleDatatypeUnrecoverableError call, else
 // the compiler attempts to merge it with other calls, losing useful information
 // in breakpad uploads.
 syncer::SyncError GenericChangeProcessor::ProcessSyncChanges(
     const tracked_objects::Location& from_here,
     const syncer::SyncChangeList& list_of_changes) {
   DCHECK(CalledOnValidThread());
   syncer::WriteTransaction trans(from_here, share_handle());
 
@@ skipping 242 matching lines @@
 void GenericChangeProcessor::StartImpl(Profile* profile) {
   DCHECK(CalledOnValidThread());
 }
 
 syncer::UserShare* GenericChangeProcessor::share_handle() const {
   DCHECK(CalledOnValidThread());
   return share_handle_;
 }
 
 }  // namespace browser_sync