Add a new API in cronet to allow setting QUIC hint after Cronet start

chromium-quic-hint-ios.diff

diff --git a/components/cronet/ios/Cronet.h b/components/cronet/ios/Cronet.h
index 05e294f238..2b4957387c 100644
--- a/components/cronet/ios/Cronet.h
+++ b/components/cronet/ios/Cronet.h
@@ -72,6 +72,10 @@ GRPC_SUPPORT_EXPORT
 // host is invalid).
 + (BOOL)addQuicHint:(NSString*)host port:(int)port altPort:(int)altPort;
 
+// Sets QUIC hint after |start| is called.
+// It is not clear yet that if this hint will override existing hint(s) or not.
++ (void)setQuicHint:(NSString*)host port:(int)port altPort:(int)altPort;
+
 // Set experimental Cronet options.  Argument is a JSON string; see
 // |URLRequestContextConfig| for more details.  This method only has
 // any effect before |start| is called.
diff --git a/components/cronet/ios/Cronet.mm b/components/cronet/ios/Cronet.mm
index e6d0fba257..d3bdb24c6c 100644
--- a/components/cronet/ios/Cronet.mm
+++ b/components/cronet/ios/Cronet.mm
@@ -372,6 +372,11 @@ new CronetHttpProtocolHandlerDelegate(
   gRequestFilterBlock = nil;
 }
 
++ (void)setQuicHint:(NSString*)host port:(int)port altPort:(int)altPort {
+    std::string quic_host = base::SysNSStringToUTF8(host);
+    gChromeNet.Get()->SetQuicHint(quic_host, port, altPort);
+}
+
 + (void)start {
   cronet::EnsureInitialized();
   [self startInternal];
diff --git a/components/cronet/ios/cronet_environment.h b/components/cronet/ios/cronet_environment.h
index 3717a4ff94..15b312a074 100644
--- a/components/cronet/ios/cronet_environment.h
+++ b/components/cronet/ios/cronet_environment.h
@@ -70,6 +70,8 @@ class CronetEnvironment {
 
   void AddQuicHint(const std::string& host, int port, int alternate_port);
 
+  void SetQuicHint(const std::string& host, int port, int alternate_port);
+
   // Setters and getters for |http2_enabled_|, |quic_enabled_|, and
   // |brotli_enabled| These only have any effect
   // before Start() is called.
@@ -156,6 +158,8 @@ class CronetEnvironment {
   void StartNetLogOnNetworkThread(const base::FilePath&, bool log_bytes);
   void StopNetLogOnNetworkThread(base::WaitableEvent* log_stopped_event);
 
+  void SetQuicHintInternal(const std::string& host, int port, int alternate_port);
+
   std::unique_ptr<base::DictionaryValue> GetNetLogInfo() const;
 
   // Returns the HttpNetworkSession object from the passed in
diff --git a/components/cronet/ios/cronet_environment.mm b/components/cronet/ios/cronet_environment.mm
index 3ec7cda2fb..31295446e1 100644
--- a/components/cronet/ios/cronet_environment.mm
+++ b/components/cronet/ios/cronet_environment.mm
@@ -419,6 +419,32 @@ bool IsNetLogPathValid(const base::FilePath& path) {
   }
 }
 
+void CronetEnvironment::SetQuicHint(const std::string& host, int port, int alternate_port) {
+    PostToNetworkThread(FROM_HERE,
+                        base::Bind(&CronetEnvironment::SetQuicHintInternal,
+                                   base::Unretained(this), host, port, alternate_port));
+}
+
+void CronetEnvironment::SetQuicHintInternal(const std::string& host, int port, int alternate_port) {
+    net::HostPortPair quic_hint(host, port);
+    url::CanonHostInfo host_info;
+    std::string canon_host(net::CanonicalizeHost(quic_hint.host(), &host_info));
+    if (!host_info.IsIPAddress() &&
+        !net::IsCanonicalizedHostCompliant(canon_host)) {
+      LOG(ERROR) << "Invalid QUIC hint host: " << quic_hint.host();
+      return;
+    }
+
+    net::AlternativeService alternative_service(net::kProtoQUIC, "",
+                                                quic_hint.port());
+
+    url::SchemeHostPort quic_hint_server("https", quic_hint.host(),
+                                         quic_hint.port());
+    main_context_->http_server_properties()->SetQuicAlternativeService(
+        quic_hint_server, net::NetworkIsolationKey(), alternative_service,
+        base::Time::Max(), quic::ParsedQuicVersionVector());
+}
+
 void CronetEnvironment::SetNetworkThreadPriority(double priority) {
   DCHECK_LE(priority, 1.0);
   DCHECK_GE(priority, 0.0);
diff --git a/components/cronet/url_request_context_config.cc b/components/cronet/url_request_context_config.cc
index 317c0b4126..f839485599 100644
--- a/components/cronet/url_request_context_config.cc
+++ b/components/cronet/url_request_context_config.cc
@@ -218,8 +218,11 @@ quic::ParsedQuicVersionVector ParseQuicVersions(
     auto it = all_supported_versions.begin();
     while (it != all_supported_versions.end()) {
       if (quic::QuicVersionToString(*it) == version) {
+        quic::HandshakeProtocol handshake_protocol = quic::PROTOCOL_QUIC_CRYPTO;
+        if (*it == quic::QUIC_VERSION_99)
+          handshake_protocol = quic::PROTOCOL_TLS1_3;
         supported_versions.push_back(
-            quic::ParsedQuicVersion(quic::PROTOCOL_QUIC_CRYPTO, *it));
+            quic::ParsedQuicVersion(handshake_protocol, *it));
         // Remove the supported version to deduplicate versions extracted from
         // |quic_versions|.
         all_supported_versions.erase(it);

please ignore the changes in components/cronet/url_request_context_config.cc.