Convert resources to take an instance key instead of an Instance*.

ppapi/cpp/private/tcp_socket_private.cc

Index: ppapi/cpp/private/tcp_socket_private.cc
diff --git a/ppapi/cpp/private/tcp_socket_private.cc b/ppapi/cpp/private/tcp_socket_private.cc
index 17938b47728b386362b7e8b6956ddb45aecf06ac..9e2c1f6ac9136f4d919f288a3c9541fde950066b 100644
--- a/ppapi/cpp/private/tcp_socket_private.cc
+++ b/ppapi/cpp/private/tcp_socket_private.cc
@@ -7,7 +7,7 @@
 #include "ppapi/c/pp_bool.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/cpp/completion_callback.h"
-#include "ppapi/cpp/instance.h"
+#include "ppapi/cpp/instance_handle.h"
 #include "ppapi/cpp/module.h"
 #include "ppapi/cpp/module_impl.h"
 
@@ -21,10 +21,10 @@ template <> const char* interface_name<PPB_TCPSocket_Private>() {
 
 }  // namespace
 
-TCPSocketPrivate::TCPSocketPrivate(Instance* instance) {
-  if (has_interface<PPB_TCPSocket_Private>() && instance) {
+TCPSocketPrivate::TCPSocketPrivate(const InstanceHandle& instance) {
+  if (has_interface<PPB_TCPSocket_Private>()) {
     PassRefFromConstructor(get_interface<PPB_TCPSocket_Private>()->Create(
-        instance->pp_instance()));
+        instance.pp_instance()));
   }
 }