Adds the new URLRequest::OnBeforeNetworkStart hook to the

content/browser/loader/resource_loader.h

Index: content/browser/loader/resource_loader.h
diff --git a/content/browser/loader/resource_loader.h b/content/browser/loader/resource_loader.h
index 55117dfbe732746d62b6b69b0bd39a12a00bb826..7245429fcce2eba15a1941f7ffc7273945df7caa 100644
--- a/content/browser/loader/resource_loader.h
+++ b/content/browser/loader/resource_loader.h
@@ -66,6 +66,8 @@ class CONTENT_EXPORT ResourceLoader : public net::URLRequest::Delegate,
   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;
@@ -117,6 +119,7 @@ class CONTENT_EXPORT ResourceLoader : public net::URLRequest::Delegate,
   enum DeferredStage {
     DEFERRED_NONE,
     DEFERRED_START,
+    DEFERRED_NETWORK_START,
     DEFERRED_REDIRECT,
     DEFERRED_READ,
     DEFERRED_FINISH