Change iOS web matcher argument types to std::string.

ios/web/shell/test/earl_grey/shell_matchers.h

Index: ios/web/shell/test/earl_grey/shell_matchers.h
diff --git a/ios/web/shell/test/earl_grey/shell_matchers.h b/ios/web/shell/test/earl_grey/shell_matchers.h
index ae9c30da33f69ed8a6d74dbb667e4231cc696c7e..b56798095762ac728a1dfb4bcfe51bd2b26498da 100644
--- a/ios/web/shell/test/earl_grey/shell_matchers.h
+++ b/ios/web/shell/test/earl_grey/shell_matchers.h
@@ -4,14 +4,24 @@
 
 #import <EarlGrey/EarlGrey.h>
 
+#include <string>
+
 namespace web {
 
+// TODO(crbug.com/614167): Remove this method when it is no longer used.
 // Shorthand for GREYMatchers::matcherForWebViewContainingText.
 id<GREYMatcher> webViewContainingText(NSString* text);
 
+// TODO(crbug.com/614167): Remove this method when it is no longer used.
 // Shorthand for GREYMatchers::matcherForAddressFieldEqualToText.
 id<GREYMatcher> addressFieldText(NSString* text);
 
+// Shorthand for GREYMatchers::matcherForWebViewContainingText.
+id<GREYMatcher> webViewContainingText(const std::string& text);
+
+// Shorthand for GREYMatchers::matcherForAddressFieldEqualToText.
+id<GREYMatcher> addressFieldText(const std::string& text);
+
 // Shorthand for GREYMatchers::matcherForBackButton.
 id<GREYMatcher> backButton();
 
@@ -26,10 +36,10 @@ id<GREYMatcher> addressField();
 @interface GREYMatchers (WebShellAdditions)
 
 // Matcher for WKWebView containing |text|.
-+ (id<GREYMatcher>)matcherForWebViewContainingText:(NSString*)text;
++ (id<GREYMatcher>)matcherForWebViewContainingText:(std::string)text;
 
 // Matcher for web shell address field text property equal to |text|.
-+ (id<GREYMatcher>)matcherForAddressFieldEqualToText:(NSString*)text;
++ (id<GREYMatcher>)matcherForAddressFieldEqualToText:(std::string)text;
 
 // Matcher for back button in web shell.
 + (id<GREYMatcher>)matcherForWebShellBackButton;