Fix some broken tests and ComboBoxElement (#8430)

testbench-api/src/main/java/com/vaadin/testbench/elements/ComboBoxElement.java

 
 import org.openqa.selenium.JavascriptExecutor;
 import org.openqa.selenium.Keys;
-import org.openqa.selenium.NoSuchElementException;
+import org.openqa.selenium.WebDriverException;
 import org.openqa.selenium.WebElement;
 
 import com.vaadin.testbench.By;
         try {
             getSuggestionPopup().findElement(byNextPage).click();
             return true;
-        } catch (NoSuchElementException e) {
+        } catch (WebDriverException e) {
+            // PhantomJS driver can throw WDE instead of the more specific
+            // NoSuchElementException
             return false;
         }
     }
         try {
             getSuggestionPopup().findElement(byPrevPage).click();
             return true;
-        } catch (NoSuchElementException e) {
+        } catch (WebDriverException e) {
+            // PhantomJS driver can throw WDE instead of the more specific
+            // NoSuchElementException
             return false;
         }
     }

uitest/src/test/java/com/vaadin/tests/components/listselect/ListSelectTest.java

 import org.openqa.selenium.WebElement;
 import org.openqa.selenium.support.ui.Select;
 
+import com.vaadin.testbench.elements.AbstractComponentElement.ReadOnlyException;
 import com.vaadin.testbench.elements.ListSelectElement;
 import com.vaadin.tests.tb3.SingleBrowserTestPhantomJS2;
 
         selectItem("Item 4");
         Assert.assertEquals(lastLogRow, getLogRow(0));
         assertNothingSelected();
+    }
+
+    @Test(expected = ReadOnlyException.class)
+    public void readOnly_selectByText() {
+        selectMenuPath("Component", "Listeners", "Selection listener");
+        selectMenuPath("Component", "State", "Readonly");
+
+        List<WebElement> select = getListSelect()
+                .findElements(By.tagName("select"));
+        Assert.assertEquals(1, select.size());
+        Assert.assertNotNull(select.get(0).getAttribute("disabled"));
 
         addItemsToSelection("Item 2");
-        Assert.assertEquals(lastLogRow, getLogRow(0));
-        assertNothingSelected();
+    }
+
+    @Test(expected = ReadOnlyException.class)
+    public void readOnly_deselectByText() {
+        selectMenuPath("Component", "Listeners", "Selection listener");
+
+        selectItem("Item 4");
+
+        selectMenuPath("Component", "State", "Readonly");
+
+        List<WebElement> select = getListSelect()
+                .findElements(By.tagName("select"));
+        Assert.assertEquals(1, select.size());
+        Assert.assertNotNull(select.get(0).getAttribute("disabled"));
 
         removeItemsFromSelection("Item 4");
-        Assert.assertEquals(lastLogRow, getLogRow(0));
-        assertNothingSelected();
     }
 
     @Test

uitest/src/test/java/com/vaadin/tests/push/PushErrorHandlingTest.java

 import org.openqa.selenium.WebElement;
 
 import com.vaadin.testbench.elements.LabelElement;
-import com.vaadin.testbench.parallel.BrowserUtil;
 import com.vaadin.testbench.parallel.TestCategory;
 import com.vaadin.tests.tb3.MultiBrowserTest;
 
         setPush(true);
         openTestURL();
         vaadinElementById("npeButton").click();
-        int idx = 1;
-        if (BrowserUtil.isPhantomJS(getDesiredCapabilities())) {
-            // PhantomJS sends an extra event when page gets loaded.
-            // This results as an extra error label.
-            ++idx;
-        }
         Assert.assertEquals(
                 "An error! Unable to invoke method click in com.vaadin.shared.ui.button.ButtonServerRpc",
-                $(LabelElement.class).get(idx).getText());
+                $(LabelElement.class).get(1).getText());
 
         WebElement table = vaadinElementById("testtable");
         WebElement row = table