Add optional arguments to our indexOf/lastIndexOf methods.

client/dom/generated/src/wrapping/_CanvasPixelArrayWrappingImplementation.dart

Index: client/dom/generated/src/wrapping/_CanvasPixelArrayWrappingImplementation.dart
===================================================================
--- client/dom/generated/src/wrapping/_CanvasPixelArrayWrappingImplementation.dart	(revision 942)
+++ client/dom/generated/src/wrapping/_CanvasPixelArrayWrappingImplementation.dart	(working copy)
@@ -42,12 +42,13 @@
     throw new UnsupportedOperationException("This object is immutable.");
   }
 
-  int indexOf(int element, int startIndex) {
+  int indexOf(int element, [int startIndex = 0]) {
     return _Lists.indexOf(this, element, startIndex, this.length);
   }
 
-  int lastIndexOf(int element, int startIndex) {
-    return _Lists.lastIndexOf(this, element, startIndex);
+  int lastIndexOf(int element, [int fromIndex = null]) {

[kasperl, 2011/10/31 12:35:09]

Why is this called fromIndex in lastIndexOf and startIndex in indexOf? I think
these names need to match to make it less surprising to use. I wonder if the
name needs to contain the word index since it's nicely encapsulated in the name
of the method too.

+    if (fromIndex === null) fromIndex = length - 1;
+    return _Lists.lastIndexOf(this, element, fromIndex);
   }
 
   int clear() {