Revert "Revert of Moving gRPC support interfaces out of cronet and into a new component. (patchset …

components/cronet/ios/cronet_environment.cc

Index: components/cronet/ios/cronet_environment.cc
diff --git a/components/cronet/ios/cronet_environment.cc b/components/cronet/ios/cronet_environment.cc
index 0fef4af2e2266ab840e1b76a457f213ba763f5a6..5e2a6eea90a154b7f1b619e8c2e460de9ce1ed46 100644
--- a/components/cronet/ios/cronet_environment.cc
+++ b/components/cronet/ios/cronet_environment.cc
@@ -96,10 +96,6 @@ class CronetURLRequestContextGetter : public net::URLRequestContextGetter {
 
 namespace cronet {
 
-bool CronetEnvironment::IsOnNetworkThread() {
-  return network_io_thread_->task_runner()->BelongsToCurrentThread();
-}
-
 void CronetEnvironment::PostToNetworkThread(
     const tracked_objects::Location& from_here,
     const base::Closure& task) {
@@ -225,6 +221,8 @@ CronetEnvironment::CronetEnvironment(const std::string& user_agent,
                                      bool user_agent_partial)
     : http2_enabled_(false),
       quic_enabled_(false),
+      event_(base::WaitableEvent::ResetPolicy::AUTOMATIC,
+             base::WaitableEvent::InitialState::NOT_SIGNALED),
       user_agent_(user_agent),
       user_agent_partial_(user_agent_partial),
       net_log_(new net::NetLog) {}
@@ -297,7 +295,6 @@ void CronetEnvironment::InitializeOnNetworkThread() {
       new net::MappedHostResolver(
           net::HostResolver::CreateDefaultResolver(nullptr)));
 
-  mapped_host_resolver->SetRulesFromString(host_resolver_rules_);
   main_context_->set_host_resolver(mapped_host_resolver.release());
 
   if (!cert_verifier_)
@@ -400,4 +397,17 @@ std::vector<uint8_t> CronetEnvironment::GetHistogramDeltas() {
   return data;
 }
 
+void CronetEnvironment::SetHostResolverRules(const std::string& rules) {
+  PostToNetworkThread(
+      FROM_HERE, base::Bind(&CronetEnvironment::SetHostResolverRulesInternal,
+                            base::Unretained(this), rules));
+  event_.Wait();

[mef, 2016/11/07 18:15:20]

Can event be allocated on the stack and passed as a bind argument? It should
remain valid until SetHostResolverRulesInternal completes.

[Garrett Casto, 2016/11/07 18:37:26]

Done.

+}
+
+void CronetEnvironment::SetHostResolverRulesInternal(const std::string& rules) {
+  static_cast<net::MappedHostResolver*>(main_context_->host_resolver())
+      ->SetRulesFromString(rules);
+  event_.Signal();
+}
+
 }  // namespace cronet