Initial PlzNavigate RDH-side logic.

content/browser/loader/navigation_url_loader_core.h

+// Copyright 2014 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_NAVIGATION_URL_LOADER_CORE_H_
+#define CONTENT_BROWSER_LOADER_NAVIGATION_URL_LOADER_CORE_H_
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/browser/loader/navigation_url_loader.h"
+
+namespace net {
+class URLRequest;
+struct RedirectInfo;
+}
+
+namespace content {
+
+class BrowserContext;
+class FrameTreeNode;
+class NavigationResourceHandler;
+class ResourceContext;
+class ResourceHandler;
+class ResourceRequestBody;
+class StreamHandle;
+struct ResourceResponse;
+
+// Part of the implementation of NavigationURLLoaderImpl. This bridges between
+// the IO and UI thread.
+class NavigationURLLoaderCore

[clamy, 2014/09/12 20:51:25]

Why do we have a NavigationURLLoaderImpl and a NavigationURLLoaderCore? Would it
be possible to just have one?

[davidben, 2014/09/19 18:30:50]

NavigationURLLoaderImpl is uniquely owned by the UI thread. The Core is some
annoying ref-counted thing shared between the two threads to deal with
synchronization. (Mostly this mirrors URLFetcher{,Impl,Core,Factory})

+    : public base::RefCountedThreadSafe<NavigationURLLoaderCore> {
+ public:
+  NavigationURLLoaderCore(NavigationURLLoader::Delegate* delegate);
+
+  // Called on the UI thread to start the request.
+  void StartRequest(BrowserContext* browser_context,
+                    int64 frame_tree_node_id,
+                    const NavigationRequestInfo& request_info,
+                    ResourceRequestBody* request_body);
+
+  // Called on the UI thread to resume a deferred redirect.
+  void Resume();
+
+  // Called on the UI thread to cancel a request, if it has not completed. No
+  // further calls will be made on |delegate_|. Note: if the response has been
+  // received, the request is considered completed from the perspective of
+  // NavigationURLLoader and ownership is transferred to the StreamHandle
+  // containing the body.
+  void Cancel();
+
+  // Called on the IO thread to set the resource handler.
+  void set_resource_handler(NavigationResourceHandler* resource_handler) {
+    resource_handler_ = resource_handler;
+  }
+
+  // Called on the IO thread when the request is redirected. The request will
+  // resume processing on the next call to Resume.
+  void RequestRedirectedOnIOThread(const net::RedirectInfo& redirect_info,
+                                   ResourceResponse* response);
+
+  // Called on the IO thread when the response started. No further calls will be
+  // made on |resource_handler_|.
+  void ResponseStartedOnIOThread(ResourceResponse* response,
+                                 scoped_ptr<StreamHandle> body);
+
+  // Called on the IO thread if the request failed before giving a response. No
+  // further calls will be made on |resource_handler_|.
+  void RequestFailedOnIOThread(int net_error);
+
+ private:
+  friend class base::RefCountedThreadSafe<NavigationURLLoaderCore>;
+
+  ~NavigationURLLoaderCore();
+
+  void StartRequestOnIOThread(ResourceContext* resource_context,
+                              int64 frame_tree_node_id,
+                              const NavigationRequestInfo& request_info,
+                              ResourceRequestBody* request_body);
+  void ResumeOnIOThread();
+  void CancelOnIOThread();
+
+  void CallOnRequestRedirected(const net::RedirectInfo& redirect_info,
+                               ResourceResponse* response);
+  void CallOnResponseStarted(ResourceResponse* response,
+                             scoped_ptr<StreamHandle> body);
+  void CallOnRequestFailed(int net_error);
+
+  NavigationURLLoader::Delegate* delegate_;
+  NavigationResourceHandler* resource_handler_;
+
+  DISALLOW_COPY_AND_ASSIGN(NavigationURLLoaderCore);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_LOADER_NAVIGATION_URL_LOADER_H_