Implement chrome.extension.connectExternal and fix various API inconsistencies.

chrome/browser/renderer_host/resource_message_filter.cc

Index: chrome/browser/renderer_host/resource_message_filter.cc
diff --git a/chrome/browser/renderer_host/resource_message_filter.cc b/chrome/browser/renderer_host/resource_message_filter.cc
index c133d68ff0b33b27f4e32914dd2da76ce85e2f4a..688179cd1ea626e3100c6f8a15adbab213d57df3 100644
--- a/chrome/browser/renderer_host/resource_message_filter.cc
+++ b/chrome/browser/renderer_host/resource_message_filter.cc
@@ -973,11 +973,13 @@ void ResourceMessageFilter::OnFreeTransportDIB(
 #endif
 
 void ResourceMessageFilter::OnOpenChannelToExtension(
-    int routing_id, const std::string& extension_id,
+    int routing_id, const std::string& source_extension_id,
+    const std::string& target_extension_id,
     const std::string& channel_name, int* port_id) {
   if (extensions_message_service_.get()) {
     *port_id = extensions_message_service_->
-        OpenChannelToExtension(routing_id, extension_id, channel_name, this);
+        OpenChannelToExtension(routing_id, source_extension_id,
+                               target_extension_id, channel_name, this);
   } else {
     *port_id = -1;
   }