Bug 1212299 followup - Fix minor grammar issue in locale text. DONTBUILD

--HG--
extra : source : dd0f0aba6e80fc9820949dda4f3bfbe81fe2a289
extra : amend_source : a71500457254332582ba1db20902b58ff11ad390

dom/locales/en-US/chrome/dom/dom.properties

@@ -67,7 +67,7 @@ nsIDOMWindowInternalWarning=Use of nsIDOMWindowInternal is deprecated. Use nsIDO
 FullScreenDeniedDisabled=Request for full-screen was denied because full-screen API is disabled by user preference.
 FullScreenDeniedFocusedPlugin=Request for full-screen was denied because a windowed plugin is focused.
 FullScreenDeniedHidden=Request for full-screen was denied because the document is no longer visible.
-FullScreenDeniedContainerNotAllowed=Request for full-screen was denied because at least one of the document's containing element is not iframe or does not have an "allowfullscreen" attribute.
+FullScreenDeniedContainerNotAllowed=Request for full-screen was denied because at least one of the document's containing elements is not an iframe or does not have an "allowfullscreen" attribute.
 FullScreenDeniedNotInputDriven=Request for full-screen was denied because Element.mozRequestFullScreen() was not called from inside a short running user-generated event handler.
 FullScreenDeniedNotInDocument=Request for full-screen was denied because requesting element is no longer in its document.
 FullScreenDeniedMovedDocument=Request for full-screen was denied because requesting element has moved document.

webapprt/locales/en-US/webapprt/overrides/dom.properties

@@ -67,7 +67,7 @@ nsIDOMWindowInternalWarning=Use of nsIDOMWindowInternal is deprecated. Use nsIDO
 FullScreenDeniedDisabled=Request for full-screen was denied because full-screen API is disabled by user preference.
 FullScreenDeniedFocusedPlugin=Request for full-screen was denied because a windowed plugin is focused.
 FullScreenDeniedHidden=Request for full-screen was denied because the document is no longer visible.
-FullScreenDeniedContainerNotAllowed=Request for full-screen was denied because at least one of the document's containing element is not iframe or does not have an "allowfullscreen" attribute.
+FullScreenDeniedContainerNotAllowed=Request for full-screen was denied because at least one of the document's containing elements is not an iframe or does not have an "allowfullscreen" attribute.
 FullScreenDeniedNotInputDriven=Request for full-screen was denied because Element.mozRequestFullScreen() was not called from inside a short running user-generated event handler.
 FullScreenDeniedNotInDocument=Request for full-screen was denied because requesting element is no longer in its document.
 FullScreenDeniedMovedDocument=Request for full-screen was denied because requesting element has moved document.