Run PDFExtensionTest.PdfAccessibilityInOOPIF with PlzNavigate.

BUG=504347
TBR=ananta@chromium.org

Review-Url: https://codereview.chromium.org/2565283006
Cr-Commit-Position: refs/heads/master@{#438296}
diff --git a/testing/buildbot/filters/browser-side-navigation.linux.browser_tests.filter b/testing/buildbot/filters/browser-side-navigation.linux.browser_tests.filter
index 400f17bf..34912ff 100644
--- a/testing/buildbot/filters/browser-side-navigation.linux.browser_tests.filter
+++ b/testing/buildbot/filters/browser-side-navigation.linux.browser_tests.filter
@@ -1,5 +1,4 @@
 -ChromeServiceWorkerTest.FallbackMainResourceRequestWhenJSDisabled
--PDFExtensionTest.PdfAccessibilityInOOPIF
 
 # https://crbug.com/652767: NavigationHandle::GetResponseHeaders sometimes
 # returns null for browser-side navigations