Remove static variables from HttpStreamFactory.

net/url_request/url_request_context.h

Index: net/url_request/url_request_context.h
diff --git a/net/url_request/url_request_context.h b/net/url_request/url_request_context.h
index 8e8e3cc902e499d98b25fa0d0a964bfa7c77e9b1..ec965e24dba41a6c4c6a37569b27e985eb7a742d 100644
--- a/net/url_request/url_request_context.h
+++ b/net/url_request/url_request_context.h
@@ -20,6 +20,7 @@
 #include "net/base/net_log.h"
 #include "net/base/ssl_config_service.h"
 #include "net/base/transport_security_state.h"
+#include "net/http/http_network_session.h"
 #include "net/http/http_server_properties.h"
 #include "net/ftp/ftp_auth_cache.h"
 #include "net/url_request/url_request.h"
@@ -52,6 +53,10 @@ class NET_EXPORT URLRequestContext
   // Copies the state from |other| into this context.
   void CopyFrom(const URLRequestContext* other);
 
+  // If this context has an associated network session, populate params from the
+  // network session and return true.
+  bool GetReferenceParams(HttpNetworkSession::Params* params) const;

[mmenke, 2012/09/04 17:43:13]

Is a copy really necessary?  Seems like we could just return a const pointer.

[mmenke, 2012/09/04 17:43:13]

Suggest calling this GetNetworkSessionParams, since that's what it actually
does, and it may be useful in more cases than for just copying parts of the
SessionParams.

[szager1, 2012/09/04 19:31:07]

The problem is that the URLRequestContext may not have an associated
HttpNetworkSession at the time this method is called (I have actually seen this
happen in the wild).  In that case, it would have to do something like return a
const reference to a static Params object containing default values.  Which
feels wrong to me; not least because the caller of GetReferenceParams can't tell
whether it actually received the default values, or values that are genuinely
associated with this context.

I could add DCHECK's to this method to ensure that this context has a non-NULL
HttpNetworkSession at the time GetReferenceParams is called, and then make sure
it's never called at the wrong time.  WDYT?

[szager1, 2012/09/04 19:31:07]

Done.

[mmenke, 2012/09/04 19:35:40]

I was thinking something more along the lines of:

const HttpNetworkSession::Params* GetReferenceParams() const;

And have it return NULL if no such params exist.

Returning a bool is nice in that it encourages checking for false, but it's not
strictly necessary.  Suppose you could do something like:

bool GetReferenceParams(HttpNetworkSession::Params* const* params) const;

But that's just weird, ugly, and I'm not event sure I got the syntax right.

+
   URLRequest* CreateRequest(
       const GURL& url, URLRequest::Delegate* delegate) const;