[Extensions] Remove the source_tab_id property on API request messages

extensions/renderer/request_sender.cc

Index: extensions/renderer/request_sender.cc
diff --git a/extensions/renderer/request_sender.cc b/extensions/renderer/request_sender.cc
index 01f054c5fc2778e55637837ec20d744c79b7b82b..896008d656ecf8371e1726c51c989cbca0262052 100644
--- a/extensions/renderer/request_sender.cc
+++ b/extensions/renderer/request_sender.cc
@@ -10,7 +10,6 @@
 #include "content/public/renderer/render_frame.h"
 #include "extensions/common/constants.h"
 #include "extensions/common/extension_messages.h"
-#include "extensions/renderer/extension_frame_helper.h"
 #include "extensions/renderer/script_context.h"
 #include "third_party/WebKit/public/web/WebDocument.h"
 #include "third_party/WebKit/public/web/WebLocalFrame.h"
@@ -95,20 +94,11 @@ bool RequestSender::StartRequest(Source* source,
                     name, source,
                     blink::WebUserGestureIndicator::currentUserGestureToken()));
 
-  int tab_id = -1;
-  if (render_frame) {
-    ExtensionFrameHelper* frame_helper =
-        ExtensionFrameHelper::Get(render_frame);
-    DCHECK(frame_helper);
-    tab_id = frame_helper->tab_id();
-  }
-
   ExtensionHostMsg_Request_Params params;
   params.name = name;
   params.arguments.Swap(value_args);
   params.extension_id = context->GetExtensionID();
   params.source_url = source_url;
-  params.source_tab_id = tab_id;
   params.request_id = request_id;
   params.has_callback = has_callback;
   params.user_gesture =