Adding field to tell if gin::IsolateHolder needs lock to be accessed.

net/proxy/proxy_resolver_v8.cc

Index: net/proxy/proxy_resolver_v8.cc
diff --git a/net/proxy/proxy_resolver_v8.cc b/net/proxy/proxy_resolver_v8.cc
index c41b1906fe94ce452f7f67551a3d299533afaab3..e004f69172dc1eaebef8417ed7104a1cfa938ed3 100644
--- a/net/proxy/proxy_resolver_v8.cc
+++ b/net/proxy/proxy_resolver_v8.cc
@@ -376,7 +376,7 @@ class SharedIsolateFactory {
         has_initialized_v8_ = true;
       }
 
-      holder_.reset(new gin::IsolateHolder);
+      holder_.reset(new gin::IsolateHolder(gin::IsolateHolder::kUseLocker));
     }
 
     return holder_->isolate();