Allow URLRequests from one context to have different NetworkDelegates.

net/url_request/url_request.h

Index: net/url_request/url_request.h
diff --git a/net/url_request/url_request.h b/net/url_request/url_request.h
index 0357c6ae803236d3f8f44be6cf03843cadd882cd..7ca27f0c5bc35a9df3166c83d379602fecc2360a 100644
--- a/net/url_request/url_request.h
+++ b/net/url_request/url_request.h
@@ -263,19 +263,17 @@ class NET_EXPORT URLRequest : NON_EXPORTED_BASE(public base::NonThreadSafe),
     virtual ~Delegate() {}
   };
 
-  // TODO(tburkard): we should get rid of this constructor, and have each
-  // creator of a URLRequest specifically list the cookie store to be used.
-  // For now, this constructor will use the cookie store in |context|.
-  URLRequest(const GURL& url,
-             RequestPriority priority,
-             Delegate* delegate,
-             const URLRequestContext* context);
-
+  // URLRequests should almost always be created by calling
+  // URLRequestContext::CreateRequest.
+  //
+  // If no cookie store or network delegate are passed in, will use the ones
+  // from the URLRequestContext.

[willchan no longer on Chromium, 2014/08/05 22:36:43]

Is it possible to be explicit all the time? Or is it too much of a PITA to fix
existing tests?

In general, I prefer being strict and explicit, rather than tolerant and falling
back. But I suspect you did this to reduce burden of updating tests, which is
valid to me. If so, that's probably worth documenting here.

[mmenke, 2014/08/05 22:42:34]

Being explicit on the cookie_store would be a huge pain (Unless I lifted that
logic into URLRequestContext::CreateRequest instead).

Being explicit on the network delegate is a 1-line change, but I thought it
would be better to be consistent with the cookie store.

Long term, as we lock down the URLRequestContext, we should hoist that logic up
to the to the URLRequestContext, and eventually get rid of it...  But I think we
should save that for when we're tearing apart the URLRequestContext /
URLRequestContextStorage, and figuring out how we want to handle that at the
same time.  The URLRequestContext may no longer keep a pointer to the cookie
store at that point, anyways.

Also, it will probably be another 3 years before we get to that point, and
someone else will probably be doing the work by then.  :)

   URLRequest(const GURL& url,
              RequestPriority priority,
              Delegate* delegate,
              const URLRequestContext* context,
-             CookieStore* cookie_store);
+             CookieStore* cookie_store,
+             NetworkDelegate* network_delegate);
 
   // If destroyed after Start() has been called but while IO is pending,
   // then the request will be effectively canceled and the delegate
@@ -702,15 +700,6 @@ class NET_EXPORT URLRequest : NON_EXPORTED_BASE(public base::NonThreadSafe),
   static void RegisterRequestInterceptor(Interceptor* interceptor);
   static void UnregisterRequestInterceptor(Interceptor* interceptor);
 
-  // Initializes the URLRequest. Code shared between the two constructors.
-  // TODO(tburkard): This can ultimately be folded into a single constructor
-  // again.
-  void Init(const GURL& url,
-            RequestPriority priotity,
-            Delegate* delegate,
-            const URLRequestContext* context,
-            CookieStore* cookie_store);
-
   // Resumes or blocks a request paused by the NetworkDelegate::OnBeforeRequest
   // handler. If |blocked| is true, the request is blocked and an error page is
   // returned indicating so. This should only be called after Start is called