Re-enable EarlGrey tests that check static error pages.

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 186 matching lines @@
   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.
-  id<GREYMatcher> webViewMatcher =
-      web::WebViewInWebState(chrome_test_util::GetCurrentWebState());
-  [[EarlGrey selectElementWithMatcher:webViewMatcher]
-      assertWithMatcher:grey_nil()];
+  // The DNS error page is static HTML content.
   NSString* const kError =
       l10n_util::GetNSString(IDS_ERRORPAGES_HEADING_NOT_AVAILABLE);
   [[EarlGrey
       selectElementWithMatcher:chrome_test_util::StaticHtmlViewContainingText(
                                    kError)] assertWithMatcher:grey_notNil()];
 }
 
 // Open the settings submenu. Assumes that settings menu is visible.
 void OpenSettingsSubMenuUnsynced(int submenu) {
   id<GREYMatcher> settings_button_matcher =
@@ skipping 285 matching lines @@
                                      TabUsageRecorder::LOAD_SUCCESS, 1,
                                      failureBlock);
   histogramTester.ExpectUniqueSample(kDidUserWaitForEvictedTabReload,
                                      TabUsageRecorder::USER_WAITED, 1,
                                      failureBlock);
   histogramTester.ExpectTotalCount(kEvictedTabReloadTime, 1, failureBlock);
 }
 
 // Verify correct recording of metrics when the reloading of an evicted tab
 // fails.
-// TODO(crbug.com/684987): Re-enable this test.
-- (void)DISABLED_testEvictedTabReloadFailure {
+- (void)testEvictedTabReloadFailure {
   web::test::SetUpFileBasedHttpServer();
   chrome_test_util::HistogramTester histogramTester;
   FailureBlock failureBlock = ^(NSString* error) {
     GREYFail(error);
   };
 
   // This URL is purposely invalid so it triggers a navigation error.
   GURL invalidURL(kTestUrl1);
 
   chrome_test_util::OpenNewTab();
@@ skipping 429 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