PlzNavigate: AppCache support.

content/browser/appcache/appcache_frame_node_navigation.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_APPCACHE_APPCACHE_FRAME_NODE_NAVIGATION_H_
+#define CONTENT_BROWSER_APPCACHE_APPCACHE_FRAME_NODE_NAVIGATION_H_
+
+#include <stdint.h>
+
+#include <memory>
+#include <vector>
+
+#include "base/macros.h"
+#include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "content/browser/appcache/appcache_backend_impl.h"
+#include "content/browser/appcache/appcache_frontend_proxy.h"
+#include "ipc/ipc_sender.h"
+
+namespace content {
+class ChromeAppCacheService;
+struct AppCacheFrameNavigationHandlerDeleter;
+
+// PlzNavigate:
+// Handles navigations for a frame. Sets up the AppCache backend for the frame

[michaeln, 2016/11/22 00:17:27]

Do we ever get multiple hosts in this backend instance?

[ananta, 2016/11/23 04:05:14]

Reverted

+// tree node id, initially. When the navigation is committed, we change the
+// mapping for the AppCache backend from a frame tree node id based mapping to
+// a renderer process id based mapping.
+class AppCacheFrameNavigationHandler
+    : public base::RefCountedThreadSafe<AppCacheFrameNavigationHandler,
+                                        AppCacheFrameNavigationHandlerDeleter>,
+      public IPC::Sender {
+ public:
+  // PlzNavigate: A pending host is registered when a navigation is initiated
+  // by the browser. The registration completes when the renderer sends the
+  // AppCacheHostMsg_RegisterHost message to us. The |frame_node_id| parameter
+  // identifies the frame node who will be a consumer of the cache.
+  // The function returns the id of the registered host. The actual host
+  // registration happens on the IO thread in the
+  // RegisterPendingHostHelper() function.
+  static int BeginNavigation(AppCacheServiceImpl* appcache_service,
+                             int frame_node_id);
+
+  // Called when the navigation initiated for |frame_node_id| is committed.
+  // The | process_id | parameter contains the ID of the renderer process.
+  static void CommitNavigation(int frame_node_id, int process_id);
+
+  // Called when the navigation initiated for |frame_node_id| fails. Cleans
+  // up any state maintained for the navigation.
+  static void FailedNavigation(int frame_node_id);
+
+  // IPC::Sender overrides.
+  // We don't expect to see calls to this function.
+  bool Send(IPC::Message* msg) override;
+
+ protected:
+  AppCacheFrameNavigationHandler(ChromeAppCacheService* appcache_service,
+                                 int frame_node_id);
+  ~AppCacheFrameNavigationHandler() override;
+
+ private:
+  // This function runs on the IO thread and registers the host identified by
+  // the |host_id| parameter as a pending host.
+  void RegisterPendingHostHelper(int host_id);
+
+  // This function runs on the IO thread and initializes the
+  // AppCacheDispatcherHost with the appcache backend information for the
+  // navigation which was initiated for the frame identified  by the
+  // frame_node_id_ member. The |process_id| parameter contains the ID of
+  // the renderer process.
+  void CommitNavigationHelper(int process_id);
+
+  // Ensure that the class is deleted on the IO thread.
+  void DeleteOnCorrectThread() const;
+
+  int frame_node_id_;
+
+  scoped_refptr<ChromeAppCacheService> appcache_service_;
+  AppCacheFrontendProxy frontend_proxy_;
+  std::unique_ptr<AppCacheBackendImpl> backend_impl_;
+
+  content::GetStatusCallback get_status_callback_;
+  content::StartUpdateCallback start_update_callback_;
+  content::SwapCacheCallback swap_cache_callback_;
+
+  friend class base::DeleteHelper<AppCacheFrameNavigationHandler>;
+  friend class base::RefCountedThreadSafe<
+      AppCacheFrameNavigationHandler,
+      AppCacheFrameNavigationHandlerDeleter>;
+  friend struct AppCacheFrameNavigationHandlerDeleter;
+
+  // Set to true when we receive a commit notification for the navigation.
+  bool commit_received_;
+
+  // WeakPtrFactory for posting tasks back to |this|.
+  base::WeakPtrFactory<AppCacheFrameNavigationHandler> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(AppCacheFrameNavigationHandler);
+};
+
+// Weak pointer references to the AppCacheFrameNavigationHandlerDeleter class
+// may be active on the IO thread. We have to make sure that we are destroyed
+// on the IO thread as well.
+struct AppCacheFrameNavigationHandlerDeleter {
+  static void Destruct(const AppCacheFrameNavigationHandler* handler) {
+    handler->DeleteOnCorrectThread();
+  }
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_APPCACHE_APPCACHE_FRAME_NODE_NAVIGATION_H_