Create base class for web shell Earl Grey tests.

ios/web/shell/test/web_shell_page_state_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 <CoreGraphics/CoreGraphics.h>
 #import <EarlGrey/EarlGrey.h>
 #import <Foundation/Foundation.h>
 #import <XCTest/XCTest.h>
 
 #import "ios/web/public/test/http_server.h"
 #include "ios/web/public/test/http_server_util.h"
 #include "ios/web/shell/test/app/navigation_test_util.h"
+#import "ios/web/shell/test/earl_grey/shell_base_test_case.h"
 #import "ios/web/shell/test/earl_grey/shell_matchers.h"
 
 #if !defined(__has_feature) || !__has_feature(objc_arc)
 #error "This file requires ARC support."
 #endif
 
 namespace {
 
 // URLs for test pages.
 const char kLongPage1[] =
@@ skipping 21 matching lines @@
       nil);
 }
 
 }  // namespace
 
 using web::shell_test_util::LoadUrl;
 using web::test::HttpServer;
 using web::webViewContainingText;
 
 // Page state test cases for the web shell.
-@interface CRWWebShellPageStateTest : XCTestCase
+@interface CRWWebShellPageStateTest : ShellBaseTestCase
+
 @end
 
 @implementation CRWWebShellPageStateTest
 
-// Set up called once for the class.
-+ (void)setUp {
-  [super setUp];
-  [[EarlGrey selectElementWithMatcher:webViewContainingText("Chromium")]
-      assertWithMatcher:grey_notNil()];
-  HttpServer::GetSharedInstance().StartOrDie();
-}
-
-// Tear down called once for the class.
-+ (void)tearDown {
-  [super tearDown];
-  HttpServer::GetSharedInstance().Stop();
-}
-
-// Tear down called after each test.
-- (void)tearDown {
-  [super tearDown];
-  HttpServer::GetSharedInstance().RemoveAllResponseProviders();
-}
-
 // Tests that page scroll position of a page is restored upon returning to the
 // page via the back/forward buttons.
 - (void)testScrollPositionRestoring {
   web::test::SetUpFileBasedHttpServer();
 
   // Load first URL which is a long page.
   LoadUrl(HttpServer::MakeUrl(kLongPage1));
   // TODO(crbug.com/629116): Remove this once |LoadUrl| waits for the load
   // completion.
   [[EarlGrey selectElementWithMatcher:webViewContainingText("List of numbers")]
@@ skipping 28 matching lines @@
       assertWithMatcher:contentOffset(CGPointMake(0, kScrollOffset1))];
 
   // Go forward and verify that the second page offset has been restored.
   [[EarlGrey selectElementWithMatcher:web::forwardButton()]
       performAction:grey_tap()];
   [[EarlGrey selectElementWithMatcher:web::webViewScrollView()]
       assertWithMatcher:contentOffset(CGPointMake(0, kScrollOffset2))];
 }
 
 @end