Implement simple http server with set cookie functionality.

ios/web/public/test/response_providers/html_response_provider_impl.h

Index: ios/web/public/test/response_providers/html_response_provider_impl.h
diff --git a/ios/web/public/test/response_providers/html_response_provider_impl.h b/ios/web/public/test/response_providers/html_response_provider_impl.h
index 53e3a60fb45c82498737bd14422c7754e6cd68a0..16991b8a9be95dc13a9890b9649c88b3d733f58e 100644
--- a/ios/web/public/test/response_providers/html_response_provider_impl.h
+++ b/ios/web/public/test/response_providers/html_response_provider_impl.h
@@ -39,6 +39,11 @@ class HtmlResponseProviderImpl {
   // response to a URL based on the mapping present in |responses|.
   explicit HtmlResponseProviderImpl(
       const std::map<GURL, std::string>& responses);
+  // Constructs an HtmlResponseProviderImpl that generates a simple string
+  // response to a URL based on the mapping present in |responses| and |cookie|.
+  explicit HtmlResponseProviderImpl(
+      const std::map<GURL, std::string>& responses,
+      const std::string& cookie);
   // Constructs an HtmlResponseProviderImpl that generates a response to a URL
   // based on the mapping present in |responses|.
   explicit HtmlResponseProviderImpl(const std::map<GURL, Response>& responses);
@@ -66,4 +71,4 @@ class HtmlResponseProviderImpl {
   const std::map<GURL, Response> responses_;
 };
 
-#endif  // IOS_WEB_PUBLIC_TEST_RESPONSE_PROVIDERS_HTML_RESPONSE_PROVIDER_IMPL_H_
+#endif  // IOS_WEB_PUBLIC_TEST_RESPONSE_PROVIDERS_HTML_RESPONSE_PROVIDER_IMPL_H_