8296592: Skip failing test StraightLineTest on Linux

Reviewed-by: angorya, arapte

tests/system/src/test/java/test/javafx/scene/web/StraightLineTest.java

@@ -27,6 +27,7 @@
 
 import com.sun.webkit.WebPage;
 import com.sun.webkit.WebPageShim;
+import com.sun.javafx.PlatformUtil;
 import javafx.application.Application;
 import javafx.application.Platform;
 import javafx.scene.Scene;
@@ -50,6 +51,7 @@
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
+import static org.junit.Assume.assumeFalse;
 
 public class StraightLineTest {
     private static final CountDownLatch launchLatch = new CountDownLatch(1);
@@ -110,6 +112,9 @@ public void setupTestObjects() {
     }
 
     @Test public void testLine() {
+        // JDK-8296590
+        assumeFalse(PlatformUtil.isLinux());
+
         final CountDownLatch webViewStateLatch = new CountDownLatch(1);
 
         Util.runAndWait(() -> {