Bug 550865 - Add Fennec strings for (CSP) Implement frame ancestor check [r=mark.finkle]

mobile/locales/en-US/chrome/overrides/appstrings.properties

@@ -62,4 +62,5 @@ externalProtocolChkMsg=Remember my choice for all links of this type.
 externalProtocolLaunchBtn=Launch application
 malwareBlocked=The site at %S has been reported as an attack site and has been blocked based on your security preferences.
 phishingBlocked=The web site at %S has been reported as a web forgery designed to trick users into sharing personal or financial information.
+cspFrameAncestorBlocked=This page has a content security policy that prevents it from being embedded in this way.
 

mobile/locales/en-US/chrome/overrides/netError.dtd

@@ -168,6 +168,9 @@ be temporary, and you can try again later.</li>
 <p>These types of web forgeries are used in scams known as phishing attacks, in which fraudulent web pages and emails are used to imitate sources you may trust.</p>
 ">
 
+<!ENTITY cspFrameAncestorBlocked.title "Blocked by Content Security Policy">
+<!ENTITY cspFrameAncestorBlocked.longDesc "<p>&brandShortName; prevented this page from loading in this way because the page has a content security policy that disallows it.</p>">
+
 <!ENTITY securityOverride.linkText "Or you can add an exception…">
 <!ENTITY securityOverride.getMeOutOfHereButton "Get me out of here!">
 <!ENTITY securityOverride.exceptionButtonLabel "Add Exception…">