Disable UndoTabModelTest#testTwoTabs on tablets.

chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/UndoTabModelTest.java

Index: chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/UndoTabModelTest.java
diff --git a/chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/UndoTabModelTest.java b/chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/UndoTabModelTest.java
index 5a66461dbfd347c38264981851d416bc20034d6a..450008e09e7430010450826c8935ed3bfbc5039d 100644
--- a/chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/UndoTabModelTest.java
+++ b/chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/UndoTabModelTest.java
@@ -8,10 +8,12 @@ import android.test.suitebuilder.annotation.MediumTest;
 
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.FlakyTest;
+import org.chromium.base.test.util.Restriction;
 import org.chromium.chrome.browser.tab.Tab;
 import org.chromium.chrome.browser.tabmodel.TabModel.TabLaunchType;
 import org.chromium.chrome.browser.tabmodel.TabModel.TabSelectionType;
 import org.chromium.chrome.test.ChromeTabbedActivityTestBase;
+import org.chromium.chrome.test.util.ChromeRestriction;
 import org.chromium.content.browser.test.util.CallbackHelper;
 import org.chromium.content_public.browser.LoadUrlParams;
 
@@ -425,6 +427,9 @@ public class UndoTabModelTest extends ChromeTabbedActivityTestBase {
      * @throws InterruptedException
      */
     @MediumTest
+    // TODO(jbudorick): Replace with DisableIf when it supports filtering by device type.
+    // Flaky on tablets, crbug.com/620014.
+    @Restriction(ChromeRestriction.RESTRICTION_TYPE_PHONE)
     public void testTwoTabs() throws InterruptedException {
         TabModel model = getActivity().getTabModelSelector().getModel(false);
         ChromeTabCreator tabCreator = getActivity().getTabCreator(false);