Upstream Chrome on iOS source code [10/11].

ios/chrome/test/earl_grey/chrome_assertions.mm

+// Copyright 2016 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 "ios/chrome/test/earl_grey/chrome_assertions.h"
+
+#import <EarlGrey/EarlGrey.h>
+
+#include "base/format_macros.h"
+#import "ios/chrome/test/app/tab_test_util.h"
+#import "ios/testing/wait_util.h"
+
+namespace chrome_test_util {
+
+void AssertMainTabCount(NSUInteger expected_tab_count) {
+  // Allow the UI to become idle, in case any tabs are being opened or closed.
+  [[GREYUIThreadExecutor sharedInstance] drainUntilIdle];
+  GREYAssert(testing::WaitUntilConditionOrTimeout(
+                 testing::kWaitForUIElementTimeout,
+                 ^{
+                   return GetMainTabCount() == expected_tab_count;
+                 }),
+             [NSString stringWithFormat:@"Did not receive %" PRIuNS " tabs",
+                                        expected_tab_count]);
+}
+
+void AssertIncognitoTabCount(NSUInteger expected_tab_count) {
+  // Allow the UI to become idle, in case any tabs are being opened or closed.
+  [[GREYUIThreadExecutor sharedInstance] drainUntilIdle];
+  ConditionBlock condition = ^{
+    return GetIncognitoTabCount() == expected_tab_count;
+  };
+  GREYAssert(
+      testing::WaitUntilConditionOrTimeout(testing::kWaitForUIElementTimeout,
+                                           condition),
+      [NSString stringWithFormat:@"Did not receive %" PRIuNS " incognito tabs",
+                                 expected_tab_count]);
+}
+
+}  // namespace chrome_test_util