Add information about sync session and other useful data to about:sync.

chrome/browser/sync/syncable/syncable.cc

 // Copyright (c) 2011 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/syncable/syncable.h"
 
 #include "build/build_config.h"
 
 #include <sys/stat.h>
 #if defined(OS_POSIX)
@@ skipping 777 matching lines @@
 }
 
 void Directory::GetDownloadProgressAsString(
     ModelType model_type,
     std::string* value_out) const {
   ScopedKernelLock lock(this);
   kernel_->persisted_info.download_progress[model_type].SerializeToString(
       value_out);
 }
 
+size_t Directory::GetEntriesCount() const {
+  return kernel_->metahandles_index ? kernel_->metahandles_index->size() : 0;
+}
+
 void Directory::SetDownloadProgress(
     ModelType model_type,
     const sync_pb::DataTypeProgressMarker& new_progress) {
   ScopedKernelLock lock(this);
   kernel_->persisted_info.download_progress[model_type].CopyFrom(new_progress);
   kernel_->info_status = KERNEL_SHARE_INFO_DIRTY;
 }
 
 bool Directory::initial_sync_ended_for_type(ModelType type) const {
   ScopedKernelLock lock(this);
@@ skipping 1133 matching lines @@
 Directory::ParentIdChildIndex::iterator
 Directory::GetParentChildIndexUpperBound(const ScopedKernelLock& lock,
                                          const Id& parent_id) {
   // The upper bound of |parent_id|'s range is the lower
   // bound of |++parent_id|'s range.
   return GetParentChildIndexLowerBound(lock,
       parent_id.GetLexicographicSuccessor());
 }
 
 }  // namespace syncable