Enable MDNS in the network service based on the feature flag in content.

Bug: chromium:875740
Cq-Include-Trybots: luci.chromium.try:linux_mojo
Change-Id: Iec6efad4b3d92877288fd29450f11ac008b26d27
Reviewed-on: https://chromium-review.googlesource.com/c/1280551Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
Commit-Queue: Zach Stein <zstein@google.com>
Cr-Commit-Position: refs/heads/master@{#603160}

content/renderer/p2p/host_address_request.cc

@@ -6,8 +6,10 @@
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
+#include "base/feature_list.h"
 #include "base/location.h"
 #include "base/threading/thread_task_runner_handle.h"
+#include "content/public/common/content_features.h"
 #include "content/renderer/p2p/socket_dispatcher.h"
 #include "jingle/glue/utils.h"
 
@@ -30,9 +32,12 @@ void P2PAsyncAddressResolver::Start(const rtc::SocketAddress& host_name,
 
   state_ = STATE_SENT;
   done_callback_ = done_callback;
+  bool enable_mdns =
+      base::FeatureList::IsEnabled(features::kWebRtcHideLocalIpsWithMdns);
   dispatcher_->GetP2PSocketManager()->get()->GetHostAddress(
-      host_name.hostname(), base::BindOnce(&P2PAsyncAddressResolver::OnResponse,
-                                           base::Unretained(this)));
+      host_name.hostname(), enable_mdns,
+      base::BindOnce(&P2PAsyncAddressResolver::OnResponse,
+                     base::Unretained(this)));
 }
 
 void P2PAsyncAddressResolver::Cancel() {

services/network/p2p/socket_manager.cc

@@ -67,8 +67,8 @@ class P2PSocketManager::DnsRequest {
  public:
   typedef base::Callback<void(const net::IPAddressList&)> DoneCallback;
 
-  explicit DnsRequest(net::HostResolver* host_resolver)
-      : resolver_(host_resolver) {}
+  DnsRequest(net::HostResolver* host_resolver, bool enable_mdns)
+      : resolver_(host_resolver), enable_mdns_(enable_mdns) {}
 
   void Resolve(const std::string& host_name,
                const DoneCallback& done_callback) {
@@ -90,9 +90,12 @@ class P2PSocketManager::DnsRequest {
       host_name_ += '.';
 
     net::HostPortPair host(host_name_, 0);
-    // TODO(crbug.com/879746): Pass in a
-    // net::HostResolver::ResolveHostParameters with source set to MDNS if we
-    // have a ".local." TLD (once MDNS is supported).
+    if (enable_mdns_) {
+      // TODO(crbug.com/879746): Pass in a
+      // net::HostResolver::ResolveHostParameters with source set to MDNS if we
+      // have a ".local." TLD and enable_mdns_ is set (once MDNS is supported).
+    }
+
     request_ =
         resolver_->CreateRequest(host, net::NetLogWithSource(), base::nullopt);
     int result = request_->Start(base::BindOnce(
@@ -124,6 +127,8 @@ class P2PSocketManager::DnsRequest {
   std::unique_ptr<net::HostResolver::ResolveHostRequest> request_;
 
   DoneCallback done_callback_;
+
+  const bool enable_mdns_;
 };
 
 P2PSocketManager::P2PSocketManager(
@@ -258,9 +263,10 @@ void P2PSocketManager::StartNetworkNotifications(
 
 void P2PSocketManager::GetHostAddress(
     const std::string& host_name,
+    bool enable_mdns,
     mojom::P2PSocketManager::GetHostAddressCallback callback) {
-  std::unique_ptr<DnsRequest> request =
-      std::make_unique<DnsRequest>(url_request_context_->host_resolver());
+  auto request = std::make_unique<DnsRequest>(
+      url_request_context_->host_resolver(), enable_mdns);
   DnsRequest* request_ptr = request.get();
   dns_requests_.insert(std::move(request));
   request_ptr->Resolve(

services/network/p2p/socket_manager.h

@@ -86,6 +86,7 @@ class P2PSocketManager
       mojom::P2PNetworkNotificationClientPtr client) override;
   void GetHostAddress(
       const std::string& host_name,
+      bool enable_mdns,
       mojom::P2PSocketManager::GetHostAddressCallback callback) override;
   void CreateSocket(P2PSocketType type,
                     const net::IPEndPoint& local_address,

services/network/public/mojom/p2p.mojom

@@ -40,7 +40,7 @@ interface P2PSocketManager {
   // Starts listening to network list changed events.
   StartNetworkNotifications(P2PNetworkNotificationClient client);
 
-  GetHostAddress(string host_name)
+  GetHostAddress(string host_name, bool enable_mdns)
       => (array<net.interfaces.IPAddress> addresses);
 
   CreateSocket(P2PSocketType type,