Make isVisible() faster and more accurate

javatests/org/chromium/distiller/DomUtilTest.java

Index: javatests/org/chromium/distiller/DomUtilTest.java
diff --git a/javatests/org/chromium/distiller/DomUtilTest.java b/javatests/org/chromium/distiller/DomUtilTest.java
index a636a5e181f8e99e66ba9ff21716f351d42758b9..20d490ead8e325b0168e5acfdbe5ec916d5edc10 100644
--- a/javatests/org/chromium/distiller/DomUtilTest.java
+++ b/javatests/org/chromium/distiller/DomUtilTest.java
@@ -345,4 +345,34 @@ public class DomUtilTest extends DomDistillerJsTestCase {
         DomUtil.stripStyleAttributes(mBody);
         assertEquals(expected, mBody.getInnerHTML());
     }
+
+    public void testIsVisibleParentDisplayNone() {
+        String html =
+            "<div style=\"display: none;\">" +
+                "<div>Some Text</div>" +
+            "</div>";
+        mBody.setInnerHTML(html);
+        Element child = mBody.getFirstChildElement().getFirstChildElement();
+        assertFalse(DomUtil.isVisible(child));
+    }
+
+    public void testIsVisibleChildDisplayNone() {
+        String html =
+            "<div>" +
+                "<div style=\"display: none;\">Some Text</div>" +
+            "</div>";
+        mBody.setInnerHTML(html);
+        Element child = mBody.getFirstChildElement().getFirstChildElement();
+        assertFalse(DomUtil.isVisible(child));
+    }
+
+    public void testIsVisibleDisplayBlock() {
+        String html =
+            "<div>" +
+                "<div>Some Text</div>" +
+            "</div>";
+        mBody.setInnerHTML(html);
+        Element child = mBody.getFirstChildElement().getFirstChildElement();
+        assertTrue(DomUtil.isVisible(child));
+    }
 }