[SYNC] Refactor SyncSourceInfo and add support in chrome invalidation client ...

chrome/browser/sync/sessions/sync_session.h

Index: chrome/browser/sync/sessions/sync_session.h
===================================================================
--- chrome/browser/sync/sessions/sync_session.h	(revision 71618)
+++ chrome/browser/sync/sessions/sync_session.h	(working copy)
@@ -15,6 +15,8 @@
 #define CHROME_BROWSER_SYNC_SESSIONS_SYNC_SESSION_H_
 #pragma once
 
+#include <map>
+#include <string>
 #include <utility>
 #include <vector>
 
@@ -35,9 +37,22 @@
 class ModelSafeWorker;
 
 namespace sessions {
-typedef std::pair<sync_pb::GetUpdatesCallerInfo::GetUpdatesSource,
-    syncable::ModelTypeBitSet> SyncSourceInfo;
+// A container for the source of a sync session. This includes the update
+// source, the datatypes triggering the sync session, and possible session
+// specific payloads which should be sent to the server.
+struct SyncSourceInfo {
+  typedef std::map<syncable::ModelType, std::string> ModelTypeMap;
+  SyncSourceInfo()
+      : updates_source(sync_pb::GetUpdatesCallerInfo::UNKNOWN) {}
+  SyncSourceInfo(
+      const sync_pb::GetUpdatesCallerInfo::GetUpdatesSource& u,
+      const ModelTypeMap& t)
+      : updates_source(u), types(t) {}
 
+  sync_pb::GetUpdatesCallerInfo::GetUpdatesSource updates_source;
+  ModelTypeMap types;
+};
+
 class SyncSession {
  public:
   // The Delegate services events that occur during the session requiring an