bug 1331320 disable e10s browser_tab_dragdrop.js in remaining linux builds r=mccr8

The intermittent abnormal plugin exit due to bug 1237853 was not detected by
opt builds due to the use of exit(1) and lack of leak checking (which would
have demonstrated bug 1309420 or bug 1239258).

The abnormal exit is now detected in opt builds also, and so this change
disables testing with these builds also.

MozReview-Commit-ID: FnBGNqnJrDp

--HG--
extra : rebase_source : 57643bf567893d460797b7a09da5ac3ebda528f4

browser/base/content/test/general/browser.ini

@@ -352,7 +352,7 @@ skip-if = os == 'linux' # Bug 1304272
 [browser_tab_detach_restore.js]
 [browser_tab_drag_drop_perwindow.js]
 [browser_tab_dragdrop.js]
-skip-if = buildapp == 'mulet' || (e10s && (debug || asan)) # Bug 1312436
+skip-if = buildapp == 'mulet' || (e10s && (debug || os == 'linux')) # Bug 1312436
 [browser_tab_dragdrop2.js]
 [browser_tabbar_big_widgets.js]
 skip-if = os == "linux" || os == "mac" # No tabs in titlebar on linux