[Sync] Update Type Info section of sync-internals.

components/sync/driver/data_type_controller.cc

Index: components/sync/driver/data_type_controller.cc
diff --git a/components/sync/driver/data_type_controller.cc b/components/sync/driver/data_type_controller.cc
index de3e7f64c490eccd1a0f65e061f0a719ab758197..79c78f743ce620df8414170f9da26103e3d2fd0a 100644
--- a/components/sync/driver/data_type_controller.cc
+++ b/components/sync/driver/data_type_controller.cc
@@ -13,14 +13,38 @@ DataTypeController::DataTypeController(ModelType type) : type_(type) {}
 
 DataTypeController::~DataTypeController() {}
 
+// static
 bool DataTypeController::IsUnrecoverableResult(ConfigureResult result) {
   return (result == UNRECOVERABLE_ERROR);
 }
 
+// static
 bool DataTypeController::IsSuccessfulResult(ConfigureResult result) {
   return (result == OK || result == OK_FIRST_RUN);
 }
 
+// static
+std::string DataTypeController::StateToString(State state) {
+  switch (state) {
+    case NOT_RUNNING:
+      return "Not Running";
+    case MODEL_STARTING:
+      return "Model Starting";
+    case MODEL_LOADED:
+      return "Model Loaded";
+    case ASSOCIATING:
+      return "Associating";
+    case RUNNING:
+      return "Running";
+    case STOPPING:
+      return "Stopping";
+    case DISABLED:
+      return "Disabled";
+  }
+  NOTREACHED();
+  return "Invalid";
+}
+
 bool DataTypeController::ReadyForStart() const {
   return true;
 }