Make PrerenderTracker's resource_throttle_io_thread_map_ use RenderFrame IDs instead of RenderView …

content/public/browser/resource_dispatcher_host_delegate.cc

Index: content/public/browser/resource_dispatcher_host_delegate.cc
===================================================================
--- content/public/browser/resource_dispatcher_host_delegate.cc	(revision 245386)
+++ content/public/browser/resource_dispatcher_host_delegate.cc	(working copy)
@@ -28,15 +28,6 @@
     ScopedVector<ResourceThrottle>* throttles) {
 }
 
-void ResourceDispatcherHostDelegate::WillTransferRequestToNewProcess(
-      int old_child_id,
-      int old_route_id,
-      int old_request_id,
-      int new_child_id,
-      int new_route_id,
-      int new_request_id) {
-}
-
 void ResourceDispatcherHostDelegate::DownloadStarting(
     net::URLRequest* request,
     ResourceContext* resource_context,