Fix all strong mode warnings in protoc-plugin

lib/protobuf_field.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of protoc;
 
 class ProtobufField {
   static final RegExp HEX_LITERAL_REGEX =
       new RegExp(r'^0x[0-9a-f]+$', multiLine: false, caseSensitive: false);
   static final RegExp INTEGER_LITERAL_REGEX = new RegExp(r'^[+-]?[0-9]+$');
@@ skipping 94 matching lines @@
 
   /// Returns Dart code adding this field to a BuilderInfo object.
   /// The call will start with ".." and a method name.
   /// [package] is the package where the code will be evaluated.
   String generateBuilderInfoCall(String package) {
     String quotedName = "'$dartFieldName'";
     String type = baseType.getDartType(package);
 
     if (isRepeated) {
       if (baseType.isMessage || baseType.isGroup) {
-        return '..pp($number, $quotedName, $typeConstant,'
+        return '..pp/*<$type>*/($number, $quotedName, $typeConstant,'
             ' $type.$checkItem, $type.create)';
       } else if (baseType.isEnum) {
-        return '..pp($number, $quotedName, $typeConstant,'
+        return '..pp/*<$type>*/($number, $quotedName, $typeConstant,'
             ' $type.$checkItem, null, $type.valueOf)';
       } else {
-        return '..p($number, $quotedName, $typeConstant)';
+        return '..p/*<$type>*/($number, $quotedName, $typeConstant)';
       }
     }
 
     String makeDefault = generateDefaultFunction(package);
     if (baseType.isEnum) {
       String valueOf = '$type.valueOf';
-      return '..e($number, $quotedName, $typeConstant, $makeDefault, $valueOf)';
+      return '..e/*<$type>*/('
+          '$number, $quotedName, $typeConstant, $makeDefault, $valueOf)';
     }
 
-    String prefix = '..a($number, $quotedName, $typeConstant';
+    String prefix = '..a/*<$type>*/($number, $quotedName, $typeConstant';
     if (makeDefault == null) return prefix + ')';
 
     if (baseType.isMessage || baseType.isGroup) {
       return prefix + ', $makeDefault, $type.create)';
     }
 
     return prefix + ', $makeDefault)';
   }
 
   /// Returns a Dart expression that evaluates to this field's default value.
   ///
   /// Returns "null" if unavailable, in which case FieldSet._getDefault()
   /// should be called instead.
   String getDefaultExpr() {
     if (isRepeated) return "null";
     switch (_field.type) {
-    case FieldDescriptorProto_Type.TYPE_BOOL:
-      return _getDefaultAsBoolExpr("false");
-    case FieldDescriptorProto_Type.TYPE_INT32:
-    case FieldDescriptorProto_Type.TYPE_UINT32:
-    case FieldDescriptorProto_Type.TYPE_SINT32:
-    case FieldDescriptorProto_Type.TYPE_FIXED32:
-    case FieldDescriptorProto_Type.TYPE_SFIXED32:
-      return _getDefaultAsInt32Expr("0");
-    case FieldDescriptorProto_Type.TYPE_STRING:
-      return _getDefaultAsStringExpr("''");
-    default:
-      return "null";
+      case FieldDescriptorProto_Type.TYPE_BOOL:
+        return _getDefaultAsBoolExpr("false");
+      case FieldDescriptorProto_Type.TYPE_INT32:
+      case FieldDescriptorProto_Type.TYPE_UINT32:
+      case FieldDescriptorProto_Type.TYPE_SINT32:
+      case FieldDescriptorProto_Type.TYPE_FIXED32:
+      case FieldDescriptorProto_Type.TYPE_SFIXED32:
+        return _getDefaultAsInt32Expr("0");
+      case FieldDescriptorProto_Type.TYPE_STRING:
+        return _getDefaultAsStringExpr("''");
+      default:
+        return "null";
     }
   }
 
   /// Returns a function expression that returns the field's default value.
   ///
   /// [package] is the package where the expression will be evaluated.
   /// Returns null if this field doesn't have an initializer.
   String generateDefaultFunction(String package) {
     if (isRepeated) {
       return '() => new PbList()';
@@ skipping 92 matching lines @@
   }
 
   get _invalidDefaultValue => "dart-protoc-plugin:"
       " invalid default value (${_field.defaultValue})"
       " found in field $fqname";
 
   _typeNotImplemented(String methodName) => "dart-protoc-plugin:"
       " $methodName not implemented for type (${_field.type})"
       " found in field $fqname";
 }