[USS] Implement SharedModelTypeProcessor::GetAllNodes for USS

components/sync/api/entity_data.h

Index: components/sync/api/entity_data.h
diff --git a/components/sync/api/entity_data.h b/components/sync/api/entity_data.h
index 99249471e7181bd1a33cfb14818b9198ee5d6292..913f2bf032c46d577ca2713032377db31fbc580e 100644
--- a/components/sync/api/entity_data.h
+++ b/components/sync/api/entity_data.h
@@ -11,6 +11,7 @@
 
 #include "base/macros.h"
 #include "base/time/time.h"
+#include "base/values.h"
 #include "components/sync/base/proto_value_ptr.h"
 #include "components/sync/protocol/sync.pb.h"
 
@@ -74,6 +75,9 @@ struct EntityData {
   // The return value must be assigned into another EntityDataPtr.
   EntityDataPtr PassToPtr() WARN_UNUSED_RESULT;
 
+  // Dumps all info into a DictionaryValue and returns it.
+  std::unique_ptr<base::DictionaryValue> ToDictionaryValue();
+
  private:
   friend struct EntityDataTraits;
   // Used to transfer the data without copying.