Refactor Assert[No]CookieExists to return a boolean

ios/chrome/test/earl_grey/chrome_earl_grey.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_earl_grey.h"
 
 #import <Foundation/Foundation.h>
 #import <WebKit/WebKit.h>
 
+#include "base/mac/foundation_util.h"
 #include "base/strings/sys_string_conversions.h"
 #import "ios/chrome/test/app/chrome_test_util.h"
 #import "ios/chrome/test/app/history_test_util.h"
 #include "ios/chrome/test/app/navigation_test_util.h"
 #import "ios/testing/wait_util.h"
 #import "ios/web/public/test/earl_grey/js_test_util.h"
 #import "ios/web/public/test/web_view_interaction_test_util.h"
 #import "ios/web/public/web_state/js/crw_js_injection_receiver.h"
 #import "ios/web/public/web_state/web_state.h"
 
@@ skipping 39 matching lines @@
 
 #pragma mark - History Utilities
 
 + (void)clearBrowsingHistory {
   chrome_test_util::ClearBrowsingHistory();
   // After clearing browsing history via code, wait for the UI to be done
   // with any updates. This includes icons from the new tab page being removed.
   [[GREYUIThreadExecutor sharedInstance] drainUntilIdle];
 }
 
+#pragma mark - Cookie Utilities
+
++ (NSDictionary*)cookies {
+  NSString* const kGetCookiesScript =
+      @"document.cookie ? document.cookie.split(/;\\s*/) : [];";
+
+  // TODO(crbug.com/690057): Remove __unsafe_unretained once all callers of
+  // |ExecuteJavaScript| are converted to ARC.
+  NSError* __unsafe_unretained error = nil;
+  id result = chrome_test_util::ExecuteJavaScript(kGetCookiesScript, &error);
+
+  GREYAssertTrue(result && !error, @"Failed to get cookies.");
+
+  NSArray* nameValuePairs = base::mac::ObjCCastStrict<NSArray>(result);
+  NSMutableDictionary* cookies = [NSMutableDictionary dictionary];
+  for (NSString* nameValuePair in nameValuePairs) {
+    NSArray* cookieNameValue = [nameValuePair componentsSeparatedByString:@"="];
+    GREYAssertEqual(2U, cookieNameValue.count, @"Cookie has invalid format.");
+
+    NSString* cookieName = cookieNameValue[0];
+    NSString* cookieValue = cookieNameValue[1];
+    cookies[cookieName] = cookieValue;
+  }
+
+  return cookies;
+}
+
 #pragma mark - Navigation Utilities
 
 + (void)loadURL:(GURL)URL {
   chrome_test_util::LoadUrl(URL);
   // Make sure that the page started loading.
   GREYAssert(chrome_test_util::IsLoading(), @"Page did not start loading.");
   [ChromeEarlGrey waitForPageToFinishLoading];
 
   web::WebState* webState = chrome_test_util::GetCurrentWebState();
   if (webState->ContentIsHTML())
@@ skipping 12 matching lines @@
 
 + (void)tapWebViewElementWithID:(NSString*)elementID {
   BOOL success =
       web::test::TapWebViewElementWithId(chrome_test_util::GetCurrentWebState(),
                                          base::SysNSStringToUTF8(elementID));
   GREYAssertTrue(success, @"Failed to tap web view element with ID: %@",
                  elementID);
 }
 
 @end