Add TabContainer to Showcase

ios/showcase/tab/sc_tab_egtest.mm

Index: ios/showcase/tab/sc_tab_egtest.mm
diff --git a/ios/showcase/tab/sc_tab_egtest.mm b/ios/showcase/tab/sc_tab_egtest.mm
new file mode 100644
index 0000000000000000000000000000000000000000..c1ab075365431d781e220d5f1ddba0d375a33960
--- /dev/null
+++ b/ios/showcase/tab/sc_tab_egtest.mm
@@ -0,0 +1,37 @@
+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#import <EarlGrey/EarlGrey.h>
+
+#import "ios/showcase/test/showcase_matchers.h"
+#import "ios/showcase/test/showcase_test_case.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+// Tests for the tab container view controller.
+@interface SCTabTestCase : ShowcaseTestCase
+@end
+
+@implementation SCTabTestCase
+
+// Tests launching TopToolbarTabViewController.
+- (void)testLaunchWithTopToolbar {
+  [[EarlGrey selectElementWithMatcher:grey_text(@"TopToolbarTabViewController")]
+      performAction:grey_tap()];
+  [[EarlGrey selectElementWithMatcher:showcase_matchers::FirstLevelBackButton()]
+      performAction:grey_tap()];
+}
+
+// Tests launching BottomToolbarTabViewController.
+- (void)testLaunchWithBottomToolbar {
+  [[EarlGrey
+      selectElementWithMatcher:grey_text(@"BottomToolbarTabViewController")]
+      performAction:grey_tap()];
+  [[EarlGrey selectElementWithMatcher:showcase_matchers::FirstLevelBackButton()]
+      performAction:grey_tap()];
+}
+
+@end