Fix flake in TabUsageRecorder egtests.

ios/chrome/browser/metrics/tab_usage_recorder_egtest.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 <EarlGrey/EarlGrey.h>
 #import <XCTest/XCTest.h>
 
 #include "base/mac/bind_objc_block.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/stringprintf.h"
@@ skipping 106 matching lines @@
 
 // Opens a new incognito tab using the UI and evicts any main tab model tabs.
 void OpenNewIncognitoTabUsingUIAndEvictMainTabs() {
   int nb_incognito_tab = chrome_test_util::GetIncognitoTabCount();
   [ChromeEarlGreyUI openToolsMenu];
   id<GREYMatcher> new_incognito_tab_button_matcher =
       grey_accessibilityID(kToolsMenuNewIncognitoTabId);
   [[EarlGrey selectElementWithMatcher:new_incognito_tab_button_matcher]
       performAction:grey_tap()];
   chrome_test_util::AssertIncognitoTabCount(nb_incognito_tab + 1);
-
+  ConditionBlock condition = ^bool {
+    return chrome_test_util::IsIncognitoMode();
+  };
+  GREYAssert(
+      testing::WaitUntilConditionOrTimeout(kWaitElementTimeout, condition),
+      @"Waiting switch to incognito mode.");
   chrome_test_util::EvictOtherTabModelTabs();
 }
 
 // Closes a tab in the current tab model. Synchronize on tab number afterwards.
 void CloseTabAtIndexAndSync(NSUInteger i) {
   NSUInteger nb_main_tab = chrome_test_util::GetMainTabCount();
   chrome_test_util::CloseTabAtIndex(i);
   ConditionBlock condition = ^{
     return chrome_test_util::GetMainTabCount() == (nb_main_tab - 1);
   };
@@ skipping 38 matching lines @@
                          IDS_IOS_SWITCH_BROWSER_MODE_LEAVE_INCOGNITO)]
           performAction:grey_tap()];
     }
   } else {
     [[EarlGrey selectElementWithMatcher:
                    chrome_test_util::buttonWithAccessibilityLabelId(
                        IDS_IOS_TOOLBAR_SHOW_TABS)] performAction:grey_tap()];
     [[EarlGrey selectElementWithMatcher:
                    chrome_test_util::buttonWithAccessibilityLabelId(
                        IDS_IOS_TOOLS_MENU_NEW_INCOGNITO_TAB)]
-        performAction:grey_swipeFastInDirection(kGREYDirectionRight)];
+        performAction:grey_swipeSlowInDirection(kGREYDirectionRight)];
     [[EarlGrey selectElementWithMatcher:
                    chrome_test_util::buttonWithAccessibilityLabelId(
                        IDS_IOS_TOOLBAR_SHOW_TABS)] performAction:grey_tap()];
   }
-  GREYAssertFalse(chrome_test_util::IsIncognitoMode(),
-                  @"Switching to normal mode failed.");
+  ConditionBlock condition = ^bool {
+    return !chrome_test_util::IsIncognitoMode();
+  };
+  GREYAssert(
+      testing::WaitUntilConditionOrTimeout(kWaitElementTimeout, condition),
+      @"Waiting switch to normal mode.");
 }
 
 // Check that the error page is visible.
 void CheckErrorPageIsVisible() {
   // The DNS error page is static HTML content, so it isn't part of the webview
   // owned by the webstate.
   [[EarlGrey selectElementWithMatcher:chrome_test_util::
                                           webViewBelongingToWebController()]
       assertWithMatcher:grey_nil()];
   NSString* const kError =
@@ skipping 744 matching lines @@
     [[GREYUIThreadExecutor sharedInstance] drainUntilIdle];
   }
   // The deleted tabs are purged during foregrounding and backgrounding.
   chrome_test_util::SimulateTabsBackgrounding();
   // Make sure |evicted_tabs_| purged the deleted tabs.
   int evicted = chrome_test_util::GetEvictedMainTabCount();
   GREYAssertEqual(evicted, 0, @"Check number of evicted tabs");
 }
 
 @end