Remove use of WebContentsImpl from ResourceDispatcherHostImpl

content/browser/loader/loader_delegate.h

 // Copyright 2016 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_LOADER_DELEGATE_H_
 #define CONTENT_BROWSER_LOADER_LOADER_DELEGATE_H_
 
 #include <inttypes.h>
 
+#include <memory>
+
+#include "content/common/content_export.h"
+#include "content/public/browser/resource_request_details.h"
 #include "net/base/load_states.h"
 
 class GURL;
 
 namespace content {
 
 // Delegate from loader to the rest of content. Lives on the IO thread.

[mmenke, 2016/06/29 15:17:12]

"Lives on the IO thread", yet the implementation is making certain assumptions
about its lifetime on the UI thread.  I'm not sure that really falls under the
definition of "lives"

[scottmg, 2016/06/29 17:55:40]

"[s]hould be interacted with" maybe? I added a comment to SetLoaderDelegate() in
RDHI too to attempt to clarify.

 //
 // This is used for breaking dependencies between content at-large and
 // content/browser/loader which will eventually be moved to a separate
 // networking service. All methods in this interface should be asynchronous,
 // since eventually this will be a Mojo interface. See https://crbug.com/622050

[mmenke, 2016/06/29 15:17:13]

In a mojo world, will we still be using render_process_id / render_frame_hosts,
or should Mojo eventually take care of that (Not sure how we'd do that - a
delegate per frame host?).

Just wondering what magic IDs we'll need to keep around, and thinking about
requests that won't have either ID, as they're not from a renderer...And
requests that will have a child_id and route_id, but no render_frame_host, if
they're from another type of process.

[scottmg, 2016/06/29 17:55:40]

I... have no idea :) I do find all the styles of int IDs a bit confusing now, so
it'd be nice if in the future things could be more directly connected to each
other in the future to avoid having a manager that dispatches amongst them.

 // and https://crbug.com/598073.
-class LoaderDelegate {
+class CONTENT_EXPORT LoaderDelegate {
  public:
   virtual ~LoaderDelegate() {}
 
   // Notification that the load state for the route identified by child_id and
   // route_id has changed.
   virtual void LoadStateChanged(int child_id,
                                 int route_id,
                                 const GURL& url,
                                 const net::LoadStateWithParam& load_state,
                                 uint64_t upload_position,
                                 uint64_t upload_size) = 0;
+
+  // Notification that a response has been received for a resource request.
+  virtual void DidGetResourceResponseStart(
+      int render_process_id,
+      int render_frame_host,
+      std::unique_ptr<ResourceRequestDetails> details) = 0;
+
+  // Notification that a redirect was received while requesting a resource.
+  virtual void DidGetRedirectForResourceRequest(
+      int render_process_id,
+      int render_frame_host,
+      std::unique_ptr<ResourceRedirectDetails> details) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_LOADER_LOADER_DELEGATE_H_