Keep track of ChannelIDService in CookieStore

chrome/browser/profiles/profile_impl_io_data.cc

Index: chrome/browser/profiles/profile_impl_io_data.cc
diff --git a/chrome/browser/profiles/profile_impl_io_data.cc b/chrome/browser/profiles/profile_impl_io_data.cc
index 0e030d6c2d36fcbd26cd4e96ffc4ab7e3436358d..522e83c8bf1f9e520033ef09bfd60ef25424408b 100644
--- a/chrome/browser/profiles/profile_impl_io_data.cc
+++ b/chrome/browser/profiles/profile_impl_io_data.cc
@@ -515,6 +515,7 @@ void ProfileImplIOData::InitializeInternal(
 
   set_channel_id_service(channel_id_service);
   main_context->set_channel_id_service(channel_id_service);
+  main_cookie_store_->SetChannelIDServiceID(channel_id_service->GetUniqueID());

[mmenke, 2016/03/18 22:12:56]

This seems weird.  We're calling into one ChannelIDService to get unique IDs for
other ChannelIDServices that are, otherwise, completely independent of the main
ChannelIDService.  Could we just have IOThread vend them directly or something? 
Open to other ideas.

[nharper, 2016/03/18 22:31:09]

I don't follow what you're saying here. This is setting a field in the main
cookie store to indicate that it should be used with the channel id service used
in the main context, so that it can be checked later that the expected channel
id service for the cookie store was indeed used. I don't see how this uses one
ChannelIDService to get unique IDs for other ChannelIDServices.

[mmenke, 2016/03/18 22:39:19]

Oh, "GetUniqueId()" was confusing me.  Was thinking it was generating a unique
ID, and you were assigning it to the channel ID service here.

 
   scoped_ptr<net::HttpCache::BackendFactory> main_backend(
       new net::HttpCache::DefaultBackend(