Gardening: mark two tests to get WebKit Linux (deps) green

fast/forms/number/number-appearance-spinbutton-disabled-readonly.html
fast/forms/select/listbox-appearance-basic.html

These two fail consistently on this bot only, not the WebKit Linux ToT bot.

BUG=353736
TEST=
TBR=zmo@chromium.org

Review URL: https://codereview.chromium.org/203443006

git-svn-id: svn://svn.chromium.org/blink/trunk@169480 bbb929c8-8fbe-4397-9dbb-9b2b20218538

third_party/WebKit/LayoutTests/TestExpectations

@@ -933,3 +933,6 @@ crbug.com/353087 w3c/web-platform-tests/shadow-dom/elements-and-dom-objects/the-
 crbug.com/353087 w3c/web-platform-tests/shadow-dom/styles/test-012.html [ Failure ]
 crbug.com/353727 virtual/threaded/animations/keyframe-timing-functions-multiple-properties.html [ Pass Timeout ]
 crbug.com/24182 [ Win ] jquery/manipulation.html [ Pass Timeout ]
+
+crbug.com/353736 [ Linux ] fast/forms/number/number-appearance-spinbutton-disabled-readonly.html [ Pass ImageOnlyFailure ]
+crbug.com/353736 [ Linux ] fast/forms/select/listbox-appearance-basic.html [ Pass ImageOnlyFailure ]