Bug 1390000 - Set prefs before loading input test page. r=esawin

Set prefs in testInputConnection itself, before we load
robocop_input.html, so the page uses new pref values.

mobile/android/tests/browser/robocop/robocop_input.html

@@ -26,11 +26,6 @@
         setTimeout(function() { designMode.contentDocument.designMode = "on" }, 0);
       }
 
-      // Spatial navigation interferes with design-mode key event tests.
-      SpecialPowers.setBoolPref("snav.enabled", false);
-      // Enable "selectionchange" events for input/textarea.
-      SpecialPowers.setBoolPref("dom.select_events.textcontrols.enabled", true);
-
       // An input that resets the editor on every input by resetting the value property.
       let resetting_input = document.getElementById("resetting-input");
       resetting_input.addEventListener("input", function() {

mobile/android/tests/browser/robocop/src/org/mozilla/gecko/tests/testInputConnection.java

@@ -30,6 +30,12 @@ public class testInputConnection extends JavascriptBridgeTest {
     public void testInputConnection() throws InterruptedException {
         GeckoHelper.blockForReady();
 
+        // Spatial navigation interferes with design-mode key event tests.
+        mActions.setPref("snav.enabled", false, /* flush */ false);
+        // Enable "selectionchange" events for input/textarea.
+        mActions.setPref("dom.select_events.enabled", true, /* flush */ false);
+        mActions.setPref("dom.select_events.textcontrols.enabled", true, /* flush */ false);
+
         final String url = mStringHelper.ROBOCOP_INPUT_URL;
         NavigationHelper.enterAndLoadUrl(url);
         mToolbar.assertTitle(url);