Format all files under tools and utils directory.

tools/dom/src/Dimension.dart

 part of html;
 
 /**
  * Class representing a
  * [length measurement](https://developer.mozilla.org/en-US/docs/Web/CSS/length)
  * in CSS.
  */
 @Experimental()
 class Dimension {
   num _value;
@@ skipping 48 matching lines @@
    * FormatError.
    */
   Dimension.css(String cssValue) {
     if (cssValue == '') cssValue = '0px';
     if (cssValue.endsWith('%')) {
       _unit = '%';
     } else {
       _unit = cssValue.substring(cssValue.length - 2);
     }
     if (cssValue.contains('.')) {
-      _value = double.parse(cssValue.substring(0,
-          cssValue.length - _unit.length));
+      _value =
+          double.parse(cssValue.substring(0, cssValue.length - _unit.length));
     } else {
       _value = int.parse(cssValue.substring(0, cssValue.length - _unit.length));
     }
   }
 
   /** Print out the CSS String representation of this value. */
   String toString() {
     return '${_value}${_unit}';
   }
 
   /** Return a unitless, numerical value of this CSS value. */
   num get value => this._value;
 }