[DRAFT] Create RenderFrameHostManager.

content/browser/loader/resource_dispatcher_host_impl.cc

Index: content/browser/loader/resource_dispatcher_host_impl.cc
diff --git a/content/browser/loader/resource_dispatcher_host_impl.cc b/content/browser/loader/resource_dispatcher_host_impl.cc
index 80356e74b0b0c4e52b9b9195cdd1e01d52e707da..710d9e1db19a3093709edcb29b93d754fc148202 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -1124,7 +1124,8 @@ void ResourceDispatcherHostImpl::BeginRequest(
   // Install a CrossSiteResourceHandler for all main frame requests.  This will
   // let us check whether a transfer is required and pause for the unload
   // handler either if so or if a cross-process navigation is already under way.
- if (request_data.resource_type == ResourceType::MAIN_FRAME &&
+ if ((request_data.resource_type == ResourceType::MAIN_FRAME ||
+      request_data.resource_type == ResourceType::SUB_FRAME) &&
      process_type == PROCESS_TYPE_RENDERER) {
     handler.reset(new CrossSiteResourceHandler(handler.Pass(), request));
   }