Add frameId to MessageSender (extension messaging API)

chrome/browser/extensions/api/messaging/message_service.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/extensions/api/messaging/message_service.h"
 
 #include "base/atomic_sequence_num.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/json/json_writer.h"
@@ skipping 101 matching lines @@
 #endif
 
 struct MessageService::MessageChannel {
   scoped_ptr<MessagePort> opener;
   scoped_ptr<MessagePort> receiver;
 };
 
 struct MessageService::OpenChannelParams {
   content::RenderProcessHost* source;
   base::DictionaryValue source_tab;
+  int source_frame_id;
   scoped_ptr<MessagePort> receiver;
   int receiver_port_id;
   std::string source_extension_id;
   std::string target_extension_id;
   GURL source_url;
   std::string channel_name;
   bool include_tls_channel_id;
   std::string tls_channel_id;
 
   // Takes ownership of receiver.
   OpenChannelParams(content::RenderProcessHost* source,
                     scoped_ptr<base::DictionaryValue> source_tab,
+                    int source_frame_id,
                     MessagePort* receiver,
                     int receiver_port_id,
                     const std::string& source_extension_id,
                     const std::string& target_extension_id,
                     const GURL& source_url,
                     const std::string& channel_name,
                     bool include_tls_channel_id)
       : source(source),
+        source_frame_id(source_frame_id),
         receiver(receiver),
         receiver_port_id(receiver_port_id),
         source_extension_id(source_extension_id),
         target_extension_id(target_extension_id),
         source_url(source_url),
         channel_name(channel_name),
         include_tls_channel_id(include_tls_channel_id) {
     if (source_tab)
       this->source_tab.Swap(source_tab.get());
   }
@@ skipping 74 matching lines @@
   return g_factory.Pointer();
 }
 
 // static
 MessageService* MessageService::Get(BrowserContext* context) {
   return BrowserContextKeyedAPIFactory<MessageService>::Get(context);
 }
 
 void MessageService::OpenChannelToExtension(
     int source_process_id, int source_routing_id, int receiver_port_id,
+    int source_frame_id,
     const std::string& source_extension_id,
     const std::string& target_extension_id,
     const GURL& source_url,
     const std::string& channel_name,
     bool include_tls_channel_id) {
   content::RenderProcessHost* source =
       content::RenderProcessHost::FromID(source_process_id);
   if (!source)
     return;
   BrowserContext* context = source->GetBrowserContext();
@@ skipping 84 matching lines @@
       MSG_ROUTING_CONTROL,
       target_extension_id);
 
   // Include info about the opener's tab (if it was a tab).
   scoped_ptr<base::DictionaryValue> source_tab;
   if (source_contents && ExtensionTabUtil::GetTabId(source_contents) >= 0) {
     // Only the tab id is useful to platform apps for internal use. The
     // unnecessary bits will be stripped out in
     // MessagingBindings::DispatchOnConnect().
     source_tab.reset(ExtensionTabUtil::CreateTabValue(source_contents));
+    DCHECK_GE(source_frame_id, 0);
+  } else {
+    source_frame_id = -1;

[not at google - send to devlin, 2014/11/10 18:36:42]

I don't like rewriting the value of parameters, it's confusing. Parameters
should be implicitly const IMO.

I don't really see any harm in passing the frame ID through here anyway.

[robwu, 2014/11/10 21:43:07]

I wanted to make it clear that the the ID is non-negative iff tab is set. But
this is already checked in the js extension bindings, so I'll remove this line.

   }
 
   OpenChannelParams* params = new OpenChannelParams(
-      source, source_tab.Pass(), receiver, receiver_port_id,
+      source, source_tab.Pass(), source_frame_id, receiver, receiver_port_id,
       source_extension_id, target_extension_id, source_url, channel_name,
       include_tls_channel_id);
 
   // If the target requests the TLS channel id, begin the lookup for it.
   // The target might also be a lazy background page, checked next, but the
   // loading of lazy background pages continues asynchronously, so enqueue
   // messages awaiting TLS channel ID first.
   if (include_tls_channel_id) {
     pending_tls_channel_id_channels_[GET_CHANNEL_ID(params->receiver_port_id)]
         = PendingMessagesQueue();
@@ skipping 115 matching lines @@
         extension_id));
   }
 
   if (contents && contents->GetController().NeedsReload()) {
     // The tab isn't loaded yet. Don't attempt to connect.
     DispatchOnDisconnect(
         source, receiver_port_id, kReceivingEndDoesntExistError);
     return;
   }
 
+  // TODO(robwu): What if the channel to a tab was created from an extension
+  // page in a tab? Then source_tab / source_frame_id / source_url could be
+  // meaningful...

[not at google - send to devlin, 2014/11/10 18:36:42]

I suppose there wouldn't be much harm in setting a source tab or frame ID if the
connection does actually come from a tab, just not a whole lot of point.

This is a good comment to include, though I'd phrase it more strongly. You could
also write it above the parameter, like

      // We don't set the source tab or frame ID for connections
      // from extensions, regardless of whether those connections
      // are from tabs, because there doesn't seem to be much point.
      scoped_ptr<base::DictionaryValue>(), -1,

though I doubt that git cl format will let you put those on the same line,
unfortunately.

[robwu, 2014/11/10 21:43:07]

It is not just those two properties, but also the URL and TLS channel ID. I'll
keep the comments and formatting as is and remove my TODO.

   scoped_ptr<OpenChannelParams> params(new OpenChannelParams(
         source,
         scoped_ptr<base::DictionaryValue>(),  // Source tab doesn't make sense
                                               // for opening to tabs.
+        -1,  // If there is no tab, then there is no frame either.
         receiver.release(),
         receiver_port_id,
         extension_id,
         extension_id,
         GURL(),  // Source URL doesn't make sense for opening to tabs.
         channel_name,
         false));  // Connections to tabs don't get TLS channel IDs.
   OpenChannelImpl(params.Pass());
 }
 
@@ skipping 22 matching lines @@
 
   AddChannel(channel, params->receiver_port_id);
 
   CHECK(channel->receiver->GetRenderProcessHost());
 
   // Send the connect event to the receiver.  Give it the opener's port ID (the
   // opener has the opposite port ID).
   channel->receiver->DispatchOnConnect(params->receiver_port_id,
                                        params->channel_name,
                                        params->source_tab,
+                                       params->source_frame_id,
                                        params->source_extension_id,
                                        params->target_extension_id,
                                        params->source_url,
                                        params->tls_channel_id);
 
   // Keep both ends of the channel alive until the channel is closed.
   channel->opener->IncrementLazyKeepaliveCount();
   channel->receiver->IncrementLazyKeepaliveCount();
   return true;
 }
@@ skipping 248 matching lines @@
 }
 
 void MessageService::DispatchOnDisconnect(content::RenderProcessHost* source,
                                           int port_id,
                                           const std::string& error_message) {
   ExtensionMessagePort port(source, MSG_ROUTING_CONTROL, "");
   port.DispatchOnDisconnect(GET_OPPOSITE_PORT_ID(port_id), error_message);
 }
 
 }  // namespace extensions