Convert Pass()→std::move() for iOS build.

ios/crnet/crnet_environment.mm

Index: ios/crnet/crnet_environment.mm
diff --git a/ios/crnet/crnet_environment.mm b/ios/crnet/crnet_environment.mm
index 3e5650f033023f07ee700449917a5e9f12a06cb0..0118dd731d40cf8e4cbf32063cdb72cbd82e0cf6 100644
--- a/ios/crnet/crnet_environment.mm
+++ b/ios/crnet/crnet_environment.mm
@@ -6,6 +6,8 @@
 
 #import <Foundation/Foundation.h>
 
+#include <utility>
+
 #include "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/files/file_path.h"
@@ -198,7 +200,7 @@ void CrNetEnvironment::StartNetLogInternal(
 
   net_log_observer_.reset(new net::WriteToFileNetLogObserver());
   net_log_observer_->set_capture_mode(capture_mode);
-  net_log_observer_->StartObserving(net_log_.get(), file.Pass(), nullptr,
+  net_log_observer_->StartObserving(net_log_.get(), std::move(file), nullptr,
                                     nullptr);
 }
 
@@ -407,7 +409,7 @@ void CrNetEnvironment::InitializeOnNetworkThread() {
           .release());
   main_context_->set_proxy_service(
       net::ProxyService::CreateUsingSystemProxyResolver(
-          proxy_config_service_.Pass(), 0, nullptr)
+          std::move(proxy_config_service_), 0, nullptr)
           .release());
 
   // Cache
@@ -455,9 +457,9 @@ void CrNetEnvironment::InitializeOnNetworkThread() {
   //                See https://crbug.com/523858.
   net::HttpNetworkSession* http_network_session =
       new net::HttpNetworkSession(params);
-  net::HttpCache* main_cache = new net::HttpCache(
-      http_network_session, main_backend.Pass(),
-      true /* set_up_quic_server_info */);
+  net::HttpCache* main_cache =
+      new net::HttpCache(http_network_session, std::move(main_backend),
+                         true /* set_up_quic_server_info */);
   main_context_->set_http_transaction_factory(main_cache);
 
   // Cookies