Add comments and CSS style for field refactor

core/css.js

@@ -299,7 +299,7 @@ Blockly.Css.CONTENT = [
     'height: 100%;',
     'margin: 0;',
     'outline: none;',
-    'padding: 2px 0px;',
+    'padding: 2px 0;',
     'width: 100%;',
     'text-align: center;',
   '}',

core/field.js

@@ -305,6 +305,7 @@ Blockly.Field.prototype.getSize = function() {
  */
 Blockly.Field.prototype.getScaledBBox_ = function() {
   var size = this.getSize();
+  // Create new object, so as to not return an uneditable SVGRect in IE.
   return new goog.math.Size(size.width * this.sourceBlock_.workspace.scale,
                             size.height * this.sourceBlock_.workspace.scale);
 };

core/field_colour.js

@@ -70,7 +70,7 @@ Blockly.FieldColour.prototype.columns_ = 0;
  */
 Blockly.FieldColour.prototype.init = function(block) {
   Blockly.FieldColour.superClass_.init.call(this, block);
-  // XXX: borderRect_ has been removed from the field.
+  // TODO(#163): borderRect_ has been removed from the field.
   // When fixing field_colour, we should re-color the shadow block instead,
   // or re-implement a rectangle in the field.
   if (this.borderRect_) {