Add web shell test to navigate with fragment link.

ios/web/shell/test/web_shell_navigation_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 <UIKit/UIKit.h>
 #import <WebKit/WebKit.h>
 #import <XCTest/XCTest.h>
 
 #import <EarlGrey/EarlGrey.h>
 
@@ skipping 51 matching lines @@
       assertWithMatcher:grey_notNil()];
 
   web::shell_test_util::TapWebViewElementWithId(
       "basic-link-navigation-to-about-blank");
 
   [[EarlGrey selectElementWithMatcher:web::addressFieldText(@"about:blank")]
       assertWithMatcher:grey_notNil()];
 }
 
 // Tests the back and forward button after entering two URLs.
-- (void)testWebScenarioBrowsingBackAndForward {
+- (void)testNavigationBackAndForward {
   // Create map of canned responses and set up the test HTML server.
   std::map<GURL, std::string> responses;
   const GURL URL1 = web::test::HttpServer::MakeUrl("http://firstURL");
   NSString* URL1Text = base::SysUTF8ToNSString(URL1.spec());
   NSString* response1 = @"Test Page 1";
   responses[URL1] = base::SysNSStringToUTF8(response1);
 
   const GURL URL2 = web::test::HttpServer::MakeUrl("http://secondURL");
   NSString* URL2Text = base::SysUTF8ToNSString(URL2.spec());
   NSString* response2 = @"Test Page 2";
@@ skipping 21 matching lines @@
       assertWithMatcher:grey_notNil()];
 
   [[EarlGrey selectElementWithMatcher:web::forwardButton()]
       performAction:grey_tap()];
   [[EarlGrey selectElementWithMatcher:web::addressFieldText(URL2Text)]
       assertWithMatcher:grey_notNil()];
   [[EarlGrey selectElementWithMatcher:web::webViewContainingText(response2)]
       assertWithMatcher:grey_notNil()];
 }
 
+// Tests back and forward navigation where a fragment link is tapped.
+- (void)testNavigationBackAndForwardAfterFragmentLink {
+  // Create map of canned responses and set up the test HTML server.
+  std::map<GURL, std::string> responses;
+  const GURL URL1 = web::test::HttpServer::MakeUrl("http://fragmentLink");
+  NSString* URL1Text = base::SysUTF8ToNSString(URL1.spec());
+  const std::string response = "<a href=\"#hash\" id=\"link\">link</a>";

[Eugene But (OOO till 7-30), 2016/05/23 20:21:58]

Optional NIT: s/\"/'

[baxley, 2016/05/23 21:18:02]

Done.

+  responses[URL1] = response;
+
+  const GURL URL2 = web::test::HttpServer::MakeUrl("http://fragmentLink/#hash");
+  NSString* URL2Text = base::SysUTF8ToNSString(URL2.spec());
+
+  web::test::SetUpSimpleHttpServer(responses);
+
+  web::shell_test_util::LoadUrl(URL1);
+  [[EarlGrey selectElementWithMatcher:web::addressFieldText(URL1Text)]

[Eugene But (OOO till 7-30), 2016/05/23 20:21:58]

Suggestion for the future:

Should |addressFieldText| take std::string instead of NSString*? This way tests
will not need to create these local variables.

[baxley, 2016/05/23 21:18:02]

That sounds reasonable. I was hesitant since the comparison is done with
NSStrings, but it probably makes sense to do the conversion inside the helper
method, rather than require every caller to do the conversion (since the typical
use-case is to create std strings for the URLs).

I was trying to avoid having it converted twice, and that doesn't seem to be an
issue.

+      assertWithMatcher:grey_notNil()];
+
+  web::shell_test_util::TapWebViewElementWithId("link");
+  [[EarlGrey selectElementWithMatcher:web::addressFieldText(URL2Text)]
+      assertWithMatcher:grey_notNil()];
+
+  [[EarlGrey selectElementWithMatcher:web::backButton()]
+      performAction:grey_tap()];
+  [[EarlGrey selectElementWithMatcher:web::addressFieldText(URL1Text)]
+      assertWithMatcher:grey_notNil()];
+
+  [[EarlGrey selectElementWithMatcher:web::forwardButton()]
+      performAction:grey_tap()];
+  [[EarlGrey selectElementWithMatcher:web::addressFieldText(URL2Text)]
+      assertWithMatcher:grey_notNil()];
+}
+
 @end