Adds the new URLRequest::OnBeforeNetworkStart hook to the

content/browser/loader/resource_loader.h

 // 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.
 
 #ifndef CONTENT_BROWSER_LOADER_RESOURCE_LOADER_H_
 #define CONTENT_BROWSER_LOADER_RESOURCE_LOADER_H_
 
 #include "base/gtest_prod_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ skipping 48 matching lines @@
   virtual void OnReceivedRedirect(net::URLRequest* request,
                                   const GURL& new_url,
                                   bool* defer) OVERRIDE;
   virtual void OnAuthRequired(net::URLRequest* request,
                               net::AuthChallengeInfo* info) OVERRIDE;
   virtual void OnCertificateRequested(net::URLRequest* request,
                                       net::SSLCertRequestInfo* info) OVERRIDE;
   virtual void OnSSLCertificateError(net::URLRequest* request,
                                      const net::SSLInfo& info,
                                      bool fatal) OVERRIDE;
+  virtual void OnBeforeNetworkStart(net::URLRequest* request,

[willchan no longer on Chromium, 2014/01/09 17:04:03]

Nit: why is this non-const? Is it desirable to allow mutations here?

[mmenke, 2014/01/09 17:52:22]

Resuming the request if you choose to pause it at this point is a non-const
operation.  It seems really weird to require you use some other pointer to the
request if you want to resume it, after having paused it at this point.

[willchan no longer on Chromium, 2014/01/09 18:00:35]

OK, that seems like a good reason. When I thought about it a bit more, the
URLRequest::Delegate is the owner after all, and so it should have non-const
access.

That said, it's not clear to me that all the ResourceLoader implementations
should have the same access. I guess if ResourceLoaders were internal to
content, I wouldn't worry. But CONTENT_EXPORT makes me think they're part of the
interface, which makes me nervous about extending the same API access to outside
consumers.

Not saying we should do it, but I think it's worth considering whether or not we
want to split out a separate implementation of URLRequest::Delegate that drives
the ResourceLoaders (I think this is RDH), and can give ResourceLoaders a const
URLRequest&, and provide Pause()/Start() APIs.

+                                    bool* defer) OVERRIDE;
   virtual void OnResponseStarted(net::URLRequest* request) OVERRIDE;
   virtual void OnReadCompleted(net::URLRequest* request,
                                int bytes_read) OVERRIDE;
 
   // SSLErrorHandler::Delegate implementation:
   virtual void CancelSSLRequest(const GlobalRequestID& id,
                                 int error,
                                 const net::SSLInfo* ssl_info) OVERRIDE;
   virtual void ContinueSSLRequest(const GlobalRequestID& id) OVERRIDE;
 
@@ skipping 31 matching lines @@
     STATUS_UNDEFINED,
     STATUS_SUCCESS_FROM_CACHE,
     STATUS_SUCCESS_FROM_NETWORK,
     STATUS_CANCELED,
     STATUS_MAX,
   };
 
   enum DeferredStage {
     DEFERRED_NONE,
     DEFERRED_START,
+    DEFERRED_NETWORK_START,
     DEFERRED_REDIRECT,
     DEFERRED_READ,
     DEFERRED_FINISH
   };
   DeferredStage deferred_stage_;
 
   scoped_ptr<net::URLRequest> request_;
   scoped_ptr<ResourceHandler> handler_;
   ResourceLoaderDelegate* delegate_;
 
@@ skipping 11 matching lines @@
   bool is_transferring_;
 
   base::WeakPtrFactory<ResourceLoader> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ResourceLoader);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_RESOURCE_LOADER_H_