Avoid calling into the ContentBrowserClient interface from ResourceDispatcherHostImpl to determine …

content/public/browser/resource_dispatcher_host.h

Index: content/public/browser/resource_dispatcher_host.h
diff --git a/content/public/browser/resource_dispatcher_host.h b/content/public/browser/resource_dispatcher_host.h
index 3bdd0cae132f4bb9dbd61c3066db169bf5e1bbf0..bcd6d2ab022f0670da86d274e77c0c9286618411 100644
--- a/content/public/browser/resource_dispatcher_host.h
+++ b/content/public/browser/resource_dispatcher_host.h
@@ -8,6 +8,7 @@
 #include <stdint.h>
 
 #include <memory>
+#include <string>
 
 #include "base/callback_forward.h"
 #include "content/common/content_export.h"
@@ -21,6 +22,7 @@ namespace content {
 class DownloadItem;
 class ResourceContext;
 class ResourceDispatcherHostDelegate;
+class ResourceDispatcherHostInterceptor;
 struct DownloadSaveInfo;
 struct Referrer;
 class RenderFrameHost;
@@ -51,6 +53,25 @@ class CONTENT_EXPORT ResourceDispatcherHost {
   // Clears the ResourceDispatcherHostLoginDelegate associated with the request.
   virtual void ClearLoginDelegateForRequest(net::URLRequest* request) = 0;
 
+  // Registers the |interceptor| for the |http_header| passed in.
+  // The |starts_with| parameter is used to match the prefix of the
+  // |http_header| in the response and the interceptor will be invoked if there
+  // is a match. If the |starts_with| parameter is empty, the interceptor will
+  // be invoked for every occurrence of the |http_header|.
+  // Currently only HTTP header based interceptors are supported.
+  // In the future to register a generic interceptor, we could pass in empty
+  // strings for the |http_header| and |starts_with| parameters.
+  // At the moment we only support one interceptor per |http_header|.
+  virtual void RegisterInterceptor(
+      const std::string& http_header,
+      const std::string& starts_with,
+      ResourceDispatcherHostInterceptor* interceptor) = 0;
+
+  // Unregisters the |interceptor| for the |http_header| passed in.
+  virtual void UnregisterInterceptor(

[jam, 2016/08/09 01:36:24]

I think we don't need this? e.g. if we get rid of the
ResourceDispatcherHostInterceptor interface and just have a callback.

[ananta, 2016/08/09 05:47:48]

Lets talk about this tomorrow. I was wondering whether with the network service
eventually converting to mojo, it may be easier to have these callbacks exposed
via a mojo interface on the client. 

If that does seem plausible, perhaps we could leave this as is.

[jam, 2016/08/09 19:58:41]

The motivation is that eventually RDH will be the mojo interface to the network
service. Mojo methods can take callbacks, so it seems sensible that this
interceptor (mojo) method would be written that way. it also simplifies this
change a little

[ananta, 2016/08/09 23:35:19]

Done.

+      const std::string& http_header,
+      ResourceDispatcherHostInterceptor* interceptor) = 0;
+
  protected:
   virtual ~ResourceDispatcherHost() {}
 };