remove trailing spaces in dart files, refs #9991

lib/base_state.dart

@@ -54,7 +54,7 @@ abstract class BaseState<T> extends State<T> {
   getHintLabel() {
     double horizontalMargin = 8.0;
     return new Container(margin: new EdgeInsets.only(top: horizontalMargin, bottom: horizontalMargin, left: verticalMargin, right: verticalMargin),
-      child: new Row(crossAxisAlignment: CrossAxisAlignment.start, 
+      child: new Row(crossAxisAlignment: CrossAxisAlignment.start,
         children: <Widget>[new Text(getHintText(), textAlign: TextAlign.left,
          style: new TextStyle(fontWeight: FontWeight.w300, color: error == null ? greyTextColor : primaryColor, fontSize: 14.0))]));
   }
@@ -63,7 +63,7 @@ abstract class BaseState<T> extends State<T> {
     if (textFieldValue.length == 0 && error == null) {
       return ' ';
     } else if (error != null) {
-      return error; 
+      return error;
     } else {
       return getHint();
     }
@@ -87,9 +87,9 @@ abstract class BaseState<T> extends State<T> {
   getPaddingForTextWidget() {
   	const double verticalPadding = 12.0;
     const double horizontalPadding = 16.0;
-  	return new EdgeInsets.only(top: verticalPadding, 
-  		bottom: verticalPadding, 
-  		left: horizontalPadding, 
+  	return new EdgeInsets.only(top: verticalPadding,
+  		bottom: verticalPadding,
+  		left: horizontalPadding,
   		right: horizontalPadding);
   }
 
@@ -126,7 +126,7 @@ abstract class BaseState<T> extends State<T> {
   Widget buildButton(EdgeInsets margin, Widget widget) {
     return new Container(margin: margin, height: buttonHeight, child: new Row(children: <Widget>[new Expanded(child: widget)]));
   }
- 
+
   Widget buildRaisedButton(BuildContext context, String text, VoidCallback onPressed) {
     return new RaisedButton(child: new Text(text,
                 style: new TextStyle(color: Colors.white)),
@@ -146,4 +146,4 @@ abstract class BaseState<T> extends State<T> {
       border: new Border.all(color: primaryColor, width: 1.0),
       borderRadius: new BorderRadius.all(new Radius.circular(4.0)));
   }
-}
+}