Rename String.concat to operator+.

samples/swarm/swarm_ui_lib/touch/FxUtil.dart

 // Copyright (c) 2011, 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 touch;
 
 /**
  * Common effects related helpers.
  */
 class FxUtil {
@@ skipping 29 matching lines @@
   static void setWebkitTransform(
       Element el, num x, num y, [num z = 0,
       num rotation = null, num scale = null,
       num originX = null, num originY = null]) {
     final style = el.style;
     // TODO(jacobr): create a helper class that simplifies building
     // transformation matricies that will be set as CSS styles. We should
     // consider using CSSMatrix although that may be overkill.
     String transform = '${TRANSLATE_3D}(${x}px,${y}px,${z}px)';
     if (rotation != null) {
-      transform = transform.concat(' ${ROTATE}(${rotation}deg)');
+      transform += ' ${ROTATE}(${rotation}deg)';
     }
     if (scale != null) {
-      transform = transform.concat(' ${SCALE}(${scale})');
+      transform += ' ${SCALE}(${scale})';
     }
     style.transform = transform;
     if (originX != null || originY != null) {
       assert(originX != null && originY != null);
       style.transformOrigin = '${originX}px ${originY}px';
     }
   }
 
   /**
    * Determine the position of an [element] relative to a [target] element.
@@ skipping 32 matching lines @@
     style.left = '${x}px';
     style.top = '${y}px';
   }
 }
 
 class TransitionTimingFunction {
   static const EASE_IN = 'ease-in';
   static const EASE_OUT = 'ease-out';
   static const EASE_IN_OUT = 'ease-in-out';
 }