[Extensions] Remove routing_id member from IOThreadExtensionFunction.

This data member is not used.

Change-Id: I4542a818349e17863ec30faab2625ee0ab1c8322
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1504953Reviewed-by: Karan Bhatia <karandeepb@chromium.org>
Commit-Queue: David Bertoni <dbertoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#638229}

extensions/browser/extension_function.cc

@@ -594,9 +594,7 @@ void UIThreadExtensionFunction::WriteToConsole(
       ->AddMessageToConsole(level, message);
 }
 
-IOThreadExtensionFunction::IOThreadExtensionFunction()
-    : routing_id_(MSG_ROUTING_NONE) {
-}
+IOThreadExtensionFunction::IOThreadExtensionFunction() {}
 
 IOThreadExtensionFunction::~IOThreadExtensionFunction() {
 }

extensions/browser/extension_function.h

@@ -609,10 +609,8 @@ class IOThreadExtensionFunction : public ExtensionFunction {
   void SetBadMessage() final;
 
   void set_ipc_sender(
-      base::WeakPtr<extensions::IOThreadExtensionMessageFilter> ipc_sender,
-      int routing_id) {
+      base::WeakPtr<extensions::IOThreadExtensionMessageFilter> ipc_sender) {
     ipc_sender_ = ipc_sender;
-    routing_id_ = routing_id;
   }
 
   base::WeakPtr<extensions::IOThreadExtensionMessageFilter> ipc_sender_weak()
@@ -620,8 +618,6 @@ class IOThreadExtensionFunction : public ExtensionFunction {
     return ipc_sender_;
   }
 
-  int routing_id() const { return routing_id_; }
-
   void set_extension_info_map(const extensions::InfoMap* extension_info_map) {
     extension_info_map_ = extension_info_map;
   }
@@ -640,7 +636,6 @@ class IOThreadExtensionFunction : public ExtensionFunction {
 
  private:
   base::WeakPtr<extensions::IOThreadExtensionMessageFilter> ipc_sender_;
-  int routing_id_;
 
   scoped_refptr<const extensions::InfoMap> extension_info_map_;
 

extensions/browser/extension_function_dispatcher.cc

@@ -300,7 +300,7 @@ void ExtensionFunctionDispatcher::DispatchOnIOThread(
     NOTREACHED();
     return;
   }
-  function_io->set_ipc_sender(ipc_sender, routing_id);
+  function_io->set_ipc_sender(ipc_sender);
   function_io->set_extension_info_map(extension_info_map);
   if (extension) {
     function->set_include_incognito_information(