[Sync] Move //components/sync to the syncer namespace.

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 ea904f79b3f1674d03d12393266ef89b903e5f5c..dd8f6d0472546342648f89a3135f29a3ed523480 100644
--- a/components/sync/core/activation_context.h
+++ b/components/sync/core/activation_context.h
@@ -12,7 +12,7 @@
 #include "components/sync/core/non_blocking_sync_common.h"
 #include "components/sync/protocol/data_type_state.pb.h"
 
-namespace syncer_v2 {
+namespace syncer {
 
 // The state passed from ModelTypeProcessor to Sync thread during DataType
 // activation.
@@ -28,6 +28,6 @@ struct ActivationContext {
   std::unique_ptr<ModelTypeProcessor> type_processor;
 };
 
-}  // namespace syncer_v2
+}  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_CORE_ACTIVATION_CONTEXT_H_