Mark deferred/fast/images/exif-orientation-css.html as flaky on Win7
Mark deferred/fast/images/exif-orientation-css.html as flaky on Win7

This test has flaked several times in a row on ImageOnlyFailures:
http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Win7%20%28dbg%29%282%29/builds/3808/steps/webkit_tests/logs/stdio

BUG=247982
TBR=alph@chromium.org

Review URL: https://codereview.chromium.org/16402017

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@152177 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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