[Sync] Rename DataTypeState to ModelTypeState.

components/sync/core/activation_context.h

Index: components/sync/core/activation_context.h
diff --git a/components/sync/core/activation_context.h b/components/sync/core/activation_context.h
index b832b029547a2d6dbf0b150eebe3772d531130db..78f6f69cc48a2c8ee226c169c933aca1f779db74 100644
--- a/components/sync/core/activation_context.h
+++ b/components/sync/core/activation_context.h
@@ -12,7 +12,7 @@
 #include "base/sequenced_task_runner.h"
 #include "components/sync/core/model_type_processor.h"
 #include "components/sync/core/non_blocking_sync_common.h"
-#include "components/sync/protocol/data_type_state.pb.h"
+#include "components/sync/protocol/model_type_state.pb.h"
 
 namespace syncer {
 
@@ -22,8 +22,8 @@ struct ActivationContext {
   ActivationContext();
   ~ActivationContext();
 
-  // Initial DataTypeState at the moment of activation.
-  sync_pb::DataTypeState data_type_state;
+  // Initial ModelTypeState at the moment of activation.
+  sync_pb::ModelTypeState model_type_state;
 
   // The ModelTypeProcessor for the worker. Note that this is owned because
   // it is generally a proxy object to the real processor.