Fixed _DomRect class to map to both ClientRect and DOMRect for browser backward compat.

[email protected],[email protected]

Change-Id: I2f5ccae15bcd993ab1e15ab556a25d6e0cd1d450
Reviewed-on: https://dart-review.googlesource.com/50504
Reviewed-by: Stephen Adams <[email protected]>
Commit-Queue: Terry Lucas <[email protected]>

Author: terrylucas

sdk/lib/html/dart2js/html_dart2js.dart

@@ -44997,7 +44997,7 @@ abstract class _DocumentType extends Node implements ChildNode {
 @DocsEditable()
 @DomName('DOMRect')
 @Experimental() // untriaged
-@Native("DOMRect")
+@Native("ClientRect,DOMRect")
 class _DomRect extends DomRectReadOnly implements Rectangle {
   // NOTE! All code below should be common with RectangleBase.
   String toString() {

tools/dom/scripts/generator.py

@@ -275,6 +275,8 @@ def ReturnValueConversionHack(idl_type, value, interface_name):
     'ChannelMergerNode': 'ChannelMergerNode,AudioChannelMerger',
     'ChannelSplitterNode': 'ChannelSplitterNode,AudioChannelSplitter',
 
+    'DOMRect': 'ClientRect,DOMRect',
+
     'DOMRectList': 'ClientRectList,DOMRectList',
 
     'CSSStyleDeclaration':