[Sync] Remove unneeded 'using syncer::' lines and 'syncer::' scopings

sync/api/sync_data.h

Index: sync/api/sync_data.h
diff --git a/sync/api/sync_data.h b/sync/api/sync_data.h
index 3bad3ae4e0bd20f0b668918f43982ded18b6aaa7..b88e0e7340a463ffb79bde13eba73c60d4d4cd62 100644
--- a/sync/api/sync_data.h
+++ b/sync/api/sync_data.h
@@ -20,8 +20,6 @@ class SyncEntity;
 
 namespace syncer {
 
-typedef syncer::ModelType SyncDataType;
-
 // A light-weight container for immutable sync data. Pass-by-value and storage
 // in STL containers are supported and encouraged if helpful.
 class SyncData {
@@ -43,7 +41,7 @@ class SyncData {
   // overwritten if the datatype is encrypted.
   static SyncData CreateLocalDelete(
       const std::string& sync_tag,
-      syncer::ModelType datatype);
+      ModelType datatype);
   static SyncData CreateLocalData(
       const std::string& sync_tag,
       const std::string& non_unique_title,
@@ -59,7 +57,7 @@ class SyncData {
 
   // Return the datatype we're holding information about. Derived from the sync
   // datatype specifics.
-  SyncDataType GetDataType() const;
+  ModelType GetDataType() const;
 
   // Return the current sync datatype specifics.
   const sync_pb::EntitySpecifics& GetSpecifics() const;
@@ -99,8 +97,7 @@ class SyncData {
     static void Swap(sync_pb::SyncEntity* t1, sync_pb::SyncEntity* t2);
   };
 
-  typedef syncer::Immutable<
-    sync_pb::SyncEntity, ImmutableSyncEntityTraits>
+  typedef Immutable<sync_pb::SyncEntity, ImmutableSyncEntityTraits>
       ImmutableSyncEntity;
 
   // Clears |entity|.
@@ -109,7 +106,7 @@ class SyncData {
   // Whether this SyncData holds valid data.
   bool is_valid_;
 
-  // Equal to syncer::kInvalidId iff this is local.
+  // Equal to kInvalidId iff this is local.
   int64 id_;
 
   // The actual shared sync entity being held.