Lengthen test timeout for entering WebVR presentation

Bug: 746541
Change-Id: I19ed588fb46b2ef1c1879ec29ed1297e21f3f036
Reviewed-on: https://chromium-review.googlesource.com/578407Reviewed-by: Yash Malik <ymalik@chromium.org>
Commit-Queue: Michael Thiessen <mthiesse@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488255}

chrome/android/javatests/src/org/chromium/chrome/browser/vr_shell/util/VrTransitionUtils.java

@@ -5,7 +5,7 @@
 package org.chromium.chrome.browser.vr_shell.util;
 
 import static org.chromium.chrome.browser.vr_shell.VrTestRule.POLL_CHECK_INTERVAL_SHORT_MS;
-import static org.chromium.chrome.browser.vr_shell.VrTestRule.POLL_TIMEOUT_SHORT_MS;
+import static org.chromium.chrome.browser.vr_shell.VrTestRule.POLL_TIMEOUT_LONG_MS;
 
 import org.junit.Assert;
 
@@ -111,7 +111,7 @@ public class VrTransitionUtils {
     public static void enterPresentationOrFail(ContentViewCore cvc) {
         enterPresentation(cvc);
         VrTestRule.pollJavaScriptBoolean(
-                "vrDisplay.isPresenting", POLL_TIMEOUT_SHORT_MS, cvc.getWebContents());
+                "vrDisplay.isPresenting", POLL_TIMEOUT_LONG_MS, cvc.getWebContents());
         Assert.assertTrue(VrShellDelegate.getVrShellForTesting().getWebVrModeEnabled());
     }
 }