Bug 1262556 - Land user-facing strings for Decoder Doctor work. r=dolske,jaws

MozReview-Commit-ID: KpzcObNwGl9

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

@@ -771,3 +771,10 @@ certErrorDetailsCertChain.label = Certificate chain:
 # %S is the group number/ID
 tabgroups.migration.anonGroup = Group %S
 tabgroups.migration.tabGroupBookmarkFolderName = Bookmarked Tab Groups
+
+decoder.noCodecs.button = Learn how
+decoder.noCodecs.accesskey = L
+decoder.noCodecs.message = To play video, you may need to install Microsoft’s Media Feature Pack.
+decoder.noCodecsXP.message = To play video, you may need to enable Adobe’s Primetime Content Decryption Module.
+decoder.noCodecsLinux.message = To play video, you may need to install the required video codecs.
+decoder.noHWAcceleration.message = To improve video quality, you may need to install Microsoft’s Media Feature Pack.