Removed IllegalAccessException and UnsupportedOperationException.

samples/ui_lib/layout/GridTracks.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.
 
 // This file has classes representing the grid tracks and grid template
 
 /**
  * The data structure representing the grid-rows or grid-columns
  * properties.
  */
@@ skipping 56 matching lines @@
   final String value;
 
   // 'start' | 'end' | 'center' | 'stretch'
   GridItemAlignment.fromString(String value)
     : this.value = (value == null) ? 'stretch' : value {
 
       switch (this.value) {
       case 'start': case 'end': case 'center': case 'stretch':
         break;
       default:
-        throw new UnsupportedOperationException(
+        throw new UnsupportedError(
             'invalid row/column alignment "$value"');
     }
   }
 
   _GridLocation align(_GridLocation span, int size) {
     switch (value) {
       case 'start':
         return new _GridLocation(span.start, size);
       case 'end':
         return new _GridLocation(span.end - size, size);
@@ skipping 42 matching lines @@
     for (final rect in _rects.getValues()) {
       rect.checkValid();
     }
   }
 
   /**
    * Looks up the given cell in the template, and returns the rect.
    */
   _GridTemplateRect lookupCell(String cell) {
     if (cell.length != 1) {
-      throw new UnsupportedOperationException(
+      throw new UnsupportedError(
           'grid-cell "$cell" must be a one character string');
     }
     final rect = _rects[cell.charCodeAt(0)];
     if (rect == null) {
-      throw new UnsupportedOperationException(
+      throw new UnsupportedError(
         'grid-cell "$cell" not found in parent\'s grid-template');
     }
     return rect;
   }
 }
 
 /** Used by GridTemplate to track a single cell's bounds. */
 class _GridTemplateRect {
   int row, column, rowSpan, columnSpan, _count, _char;
   _GridTemplateRect(this._char, this.row, this.column)
     : rowSpan = 1, columnSpan = 1, _count = 1 {}
 
   void add(int r, int c) {
     assert (r >= row && c >= column);
     _count++;
     rowSpan = Math.max(rowSpan, r - row + 1);
     columnSpan = Math.max(columnSpan, c - column + 1);
   }
 
   void checkValid() {
     int expected = rowSpan * columnSpan;
     if (expected != _count) {
       // TODO(jmesserly): not sure if we should throw here, due to CSS's
       // permissiveness. At the moment we're noisy about errors.
       String cell = new String.fromCharCodes([_char]);
-      throw new UnsupportedOperationException('grid-template "$cell"'
+      throw new UnsupportedError('grid-template "$cell"'
           ' is not square, expected $expected cells but got $_count');
     }
   }
 }
 
 
 /**
  * Used to return a row/column and span during parsing of grid-row and
  * grid-column during parsing.
  */
 class _GridLocation {
   final int start, length;
   _GridLocation(this.start, this.length) {}
 
   int get end => start + length;
 }