Move Rectangle and Point into dart:math.

tools/dom/templates/html/impl/impl_CanvasRenderingContext2D.darttemplate

 // Copyright (c) 2012, 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 $LIBRARYNAME;
 
 $(ANNOTATIONS)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS$NATIVESPEC {
 $!MEMBERS
 
   /**
@@ skipping 50 matching lines @@
    * If the image is larger than canvas
    * will allow, the image will be clipped to fit the available space.
    *
    *     CanvasElement canvas = new CanvasElement(width: 600, height: 600);
    *     CanvasRenderingContext2D ctx = canvas.context2D;
    *     ImageElement img = document.query('img');
    *     img.width = 100;
    *     img.height = 100;
    *
    *     // Scale the image to 20x20.
-   *     ctx.drawImageToRect(img, new Rect(50, 50, 20, 20));
+   *     ctx.drawImageToRect(img, new Rectangle(50, 50, 20, 20));
    *
    *     VideoElement video = document.query('video');
    *     video.width = 100;
    *     video.height = 100;
    *     // Take the middle 20x20 pixels from the video and stretch them.
-   *     ctx.drawImageToRect(video, new Rect(50, 50, 100, 100),
-   *         sourceRect: new Rect(40, 40, 20, 20));
+   *     ctx.drawImageToRect(video, new Rectangle(50, 50, 100, 100),
+   *         sourceRect: new Rectangle(40, 40, 20, 20));
    *
    *     // Draw the top 100x20 pixels from the otherCanvas.
    *     CanvasElement otherCanvas = document.query('canvas');
-   *     ctx.drawImageToRect(otherCanvas, new Rect(0, 0, 100, 20),
-   *         sourceRect: new Rect(0, 0, 100, 20));
+   *     ctx.drawImageToRect(otherCanvas, new Rectangle(0, 0, 100, 20),
+   *         sourceRect: new Rectangle(0, 0, 100, 20));
    *
    * See also:
    *
    *   * [CanvasImageSource] for more information on what data is retrieved
    * from [source].
    *   * [drawImage](http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-context-2d-drawimage)
    * from the WHATWG.
    */
   @DomName('CanvasRenderingContext2D.drawImage')
-  void drawImageToRect(CanvasImageSource source, Rect destRect,
-      {Rect sourceRect}) {
+  void drawImageToRect(CanvasImageSource source, Rectangle destRect,
+      {Rectangle sourceRect}) {
 $if DART2JS
     if (sourceRect == null) {
       drawImageScaled(source,
           destRect.left,
           destRect.top,
           destRect.width,
           destRect.height);
     } else {
       drawImageScaledFromSource(source,
           sourceRect.left,
@@ skipping 155 matching lines @@
   @DomName('CanvasRenderingContext2D.lineDashOffset')
   void set lineDashOffset(num value) => JS('void',
       'typeof #.lineDashOffset != "undefined" ? #.lineDashOffset = # : '
       '#.webkitLineDashOffset = #', this, this, value, this, value);
 $else
   // TODO(amouravski): Add Dartium native methods for drawImage once we figure
   // out how to not break native bindings.
 $endif
 }