[Cronet] Add API to set DNS cache entry

components/cronet/android/cronet_url_request_context_adapter.cc

Index: components/cronet/android/cronet_url_request_context_adapter.cc
diff --git a/components/cronet/android/cronet_url_request_context_adapter.cc b/components/cronet/android/cronet_url_request_context_adapter.cc
index 9e1ebfe059390cd22dc31f505f9920692b8065ce..55678c1d814205f31e41a9b2346e3ff6a8d13513 100644
--- a/components/cronet/android/cronet_url_request_context_adapter.cc
+++ b/components/cronet/android/cronet_url_request_context_adapter.cc
@@ -55,6 +55,7 @@
 #include "net/cert/caching_cert_verifier.h"
 #include "net/cert/cert_verifier.h"
 #include "net/cookies/cookie_monster.h"
+#include "net/dns/host_cache.h"
 #include "net/http/http_auth_handler_factory.h"
 #include "net/http/http_server_properties_manager.h"
 #include "net/log/file_net_log_observer.h"
@@ -599,6 +600,48 @@ void CronetURLRequestContextAdapter::ProvideThroughputObservations(
                             base::Unretained(this), should));
 }
 
+void CronetURLRequestContextAdapter::PutHostCacheOnNetworkThread(
+    std::string hostname,
+    net::AddressList address_list,
+    base::TimeDelta ttl) {
+  DCHECK(GetNetworkTaskRunner()->BelongsToCurrentThread());
+  net::HostCache::Key key(hostname, net::ADDRESS_FAMILY_UNSPECIFIED, 0);
+  net::HostCache::Entry entry(net::OK, address_list, ttl);
+  context_->host_resolver()->GetHostCache()->Set(key, entry,
+                                                 base::TimeTicks::Now(), ttl);
+}
+
+void CronetURLRequestContextAdapter::PutHostCache(
+    JNIEnv* env,
+    const base::android::JavaParamRef<jobject>& jcaller,
+    const base::android::JavaParamRef<jstring>& jhostname,
+    const base::android::JavaParamRef<jobjectArray>& jaddresses,
+    jint jseconds_to_live) {
+  size_t address_count = env->GetArrayLength(jaddresses);
+  net::AddressList address_list;
+  for (size_t i = 0; i < address_count; ++i) {
+    ScopedJavaLocalRef<jbyteArray> bytes_array(
+        env,
+        static_cast<jbyteArray>(env->GetObjectArrayElement(jaddresses, i)));
+    size_t address_size = env->GetArrayLength(bytes_array.obj());
+    if (address_size != net::IPAddress::kIPv4AddressSize &&
+        address_size != net::IPAddress::kIPv6AddressSize) {
+      LOG(ERROR) << "Unsupported IP address size: " << address_size;
+      return;
+    }
+    jbyte* bytes = env->GetByteArrayElements(bytes_array.obj(), nullptr);
+    address_list.push_back(net::IPEndPoint(
+        net::IPAddress(reinterpret_cast<uint8_t*>(bytes), address_size), 0));
+    env->ReleaseByteArrayElements(bytes_array.obj(), bytes, JNI_ABORT);
+  }
+  PostTaskToNetworkThread(
+      FROM_HERE,
+      base::Bind(&CronetURLRequestContextAdapter::PutHostCacheOnNetworkThread,
+                 base::Unretained(this),
+                 base::android::ConvertJavaStringToUTF8(env, jhostname),
+                 address_list, base::TimeDelta::FromSeconds(jseconds_to_live)));
+}
+
 void CronetURLRequestContextAdapter::InitializeOnNetworkThread(
     std::unique_ptr<URLRequestContextConfig> config,
     const base::android::ScopedJavaGlobalRef<jobject>&