Bug 1432122 - add nosniff header to map file for sourcemaps test;r=test-only

MozReview-Commit-ID: 5uEaZxUgLfH

--HG--
extra : rebase_source : be1c4fce275b4778c50639735d39b7506101e6d2

devtools/client/styleeditor/test/browser.ini

@@ -36,11 +36,14 @@ support-files =
   sourcemap-css/contained.css
   sourcemap-css/sourcemaps.css
   sourcemap-css/sourcemaps.css.map
+  # add nosniff header to test against Bug 1330383
+  sourcemap-css/sourcemaps.css.map^headers^
   sourcemap-css/media-rules.css
   sourcemap-css/media-rules.css.map
   sourcemap-css/test-bootstrap-scss.css
   sourcemap-css/test-stylus.css
   sourcemap-sass/sourcemaps.scss
+  # add nosniff header to test against Bug 1330383
   sourcemap-sass/sourcemaps.scss^headers^
   sourcemap-sass/media-rules.scss
   sourcemap-styl/test-stylus.styl

devtools/client/styleeditor/test/sourcemap-css/sourcemaps.css.map^headers^

@@ -0,0 +1,2 @@
+X-Content-Type-Options: nosniff
+Content-Type: text/plain