Add frameId to MessageSender (extension messaging API)

extensions/common/extension_messages.h

Index: extensions/common/extension_messages.h
diff --git a/extensions/common/extension_messages.h b/extensions/common/extension_messages.h
index 45160b61360beffa7d41e0315bfac127f1e3e771..ee23e7ae8eea88e7e1217308d302c7f38e980c03 100644
--- a/extensions/common/extension_messages.h
+++ b/extensions/common/extension_messages.h
@@ -147,6 +147,17 @@ IPC_STRUCT_BEGIN(ExtensionMsg_ExecuteCode_Params)
   IPC_STRUCT_MEMBER(bool, user_gesture)
 IPC_STRUCT_END()
 
+// Struct containing information about the sender of connect() calls that
+// originate from a tab.
+IPC_STRUCT_BEGIN(ExtensionMsg_TabConnectionInfo)
+  // The tab from where the connection was created.
+  IPC_STRUCT_MEMBER(base::DictionaryValue, tab)
+
+  // The ID of the frame that initiated the connection.
+  // 0 if main frame, positive otherwise. -1 if not initiated from a frame.
+  IPC_STRUCT_MEMBER(int, frame_id)
+IPC_STRUCT_END()
+
 // Struct containing the data for external connections to extensions. Used to
 // handle the IPCs initiated by both connect() and onConnect().
 IPC_STRUCT_BEGIN(ExtensionMsg_ExternalConnectionInfo)
@@ -487,7 +498,7 @@ IPC_MESSAGE_ROUTED2(ExtensionMsg_GetAppInstallStateResponse,
 IPC_MESSAGE_ROUTED5(ExtensionMsg_DispatchOnConnect,

[not at google - send to devlin, 2014/11/11 00:03:04]

It is actually more standard to just pull all of these arguments into a struct.
The reason for the ExtensionMsg_ExternalConnectionInfo being separate like that
is because it's used in 2 places.

But the way you have it is fine, too.

                     int /* target_port_id */,
                     std::string /* channel_name */,
-                    base::DictionaryValue /* source_tab */,
+                    ExtensionMsg_TabConnectionInfo /* source */,
                     ExtensionMsg_ExternalConnectionInfo,
                     std::string /* tls_channel_id */)