linux: fix a layout test by having our test plugin provide two mimetypes

webkit/tools/layout_tests/test_expectations.txt

 // This file consists of lines with specifications of what
 // to expect from layout test cases. The test cases can be directories
 // in which case the expectations apply to all test cases in that
 // directory and any subdirectory. The format of the file is along the
 // lines of:
 //
 // LayoutTests/fast/js/fixme.js = FAIL
 // LayoutTests/fast/js/flaky.js = FAIL PASS
 // LayoutTests/fast/js/crash.js = CRASH TIMEOUT FAIL PASS
 //
@@ skipping 1245 matching lines @@
 BUG15797 LINUX : LayoutTests/plugins/embed-attributes-setting.html = FAIL
 
 // Depends on plugin support.
 BUG10351 MAC : LayoutTests/fast/dom/Window/Plug-ins.html = FAIL
 BUG10351 MAC : LayoutTests/fast/js/navigator-mimeTypes-length.html = FAIL
 BUG10351 MAC : LayoutTests/accessibility/plugin.html = FAIL CRASH
 BUG10351 MAC : LayoutTests/fast/dom/object-embed-plugin-scripting.html = FAIL
 BUG10351 MAC : LayoutTests/fast/events/tabindex-focus-blur-all.html = FAIL PASS
 BUG10351 MAC : LayoutTests/tables/mozilla_expected_failures/bugs/bug8499.html = FAIL
 BUG10673 MAC : chrome/plugins/call-as-function.html = FAIL
-// Linux: This test verifies that a single plugin has multiple mime-types.
-// Our test plugin doesn't.  Maybe we should add an extra one?
-BUG10351 LINUX : LayoutTests/fast/js/navigator-mimeTypes-length.html = FAIL
 BUG10351 MAC : LayoutTests/http/tests/plugins/cross-frame-object-access.html = FAIL
 // Skip because we throw an exception before we get to dumpAsText.
 BUG10351 SKIP MAC : LayoutTests/http/tests/plugins/geturlnotify-from-npp-destroystream.html = FAIL
 BUG10351 MAC : LayoutTests/plugins/embed-attributes-setting.html = CRASH FAIL
 BUG10351 MAC : LayoutTests/plugins/embed-inside-object.html = TIMEOUT
 BUG10351 MAC : LayoutTests/plugins/get-empty-url.html = CRASH FAIL
 BUG10351 MAC : LayoutTests/plugins/get-url-that-the-resource-load-delegate-will-disallow.html = FAIL
 BUG10351 MAC : LayoutTests/plugins/getintidentifier-special-values.html = FAIL
 BUG10351 MAC : LayoutTests/plugins/geturl-replace-query.html = TIMEOUT
 BUG10351 MAC : LayoutTests/plugins/inner-html-display-none.html = FAIL
@@ skipping 1533 matching lines @@
 BUG15780 : LayoutTests/fast/repaint/4774354.html = FAIL TIMEOUT
 BUG15780 : LayoutTests/fast/forms/tabbing-input-iframe.html = FAIL
 BUG15780 : LayoutTests/fast/overflow/scrollRevealButton.html = FAIL
 // Re-enable once the (more broad) duplicates (in the above section) are gone.
 // BUG10384 MAC : LayoutTests/fast/events/frame-tab-focus.html = CRASH FAIL
 // BUG11613 LINUX : LayoutTests/fast/forms/tabbing-input-iframe.html = FAIL
 // BUG11613 LINUX : LayoutTests/fast/overflow/scrollRevealButton.html = FAIL
 
 // WebKit 45460:45473
 BUG15837 : LayoutTests/http/tests/security/xssAuditor/script-tag-null-char.html = FAIL