diff -r 000000000000 -r 6474c204b198 dom/locales/en-US/chrome/layout/layout_errors.properties
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/locales/en-US/chrome/layout/layout_errors.properties	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,11 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+ImageMapRectBoundsError=The "coords" attribute of the <area shape="rect"> tag is not in the "left,top,right,bottom" format.
+ImageMapCircleWrongNumberOfCoords=The "coords" attribute of the <area shape="circle"> tag is not in the "center-x,center-y,radius" format.
+ImageMapCircleNegativeRadius=The "coords" attribute of the <area shape="circle"> tag has a negative radius.
+ImageMapPolyWrongNumberOfCoords=The "coords" attribute of the <area shape="poly"> tag is not in the "x1,y1,x2,y2 …" format.
+ImageMapPolyOddNumberOfCoords=The "coords" attribute of the <area shape="poly"> tag is missing the last "y" coordinate (the correct format is "x1,y1,x2,y2 …").
+
+TablePartRelPosWarning=Relative positioning of table rows and row groups is now supported. This site may need to be updated because it may depend on this feature having no effect.