[Presentation API] (3rd) (1-UA) Split PresentationServiceDelegateImpl(PSDImpl)

chrome/browser/media/router/receiver_presentation_service_delegate_impl.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 CHROME_BROWSER_MEDIA_ROUTER_RECEIVER_PRESENTATION_SERVICE_DELEGATE_IMPL_H_
+#define CHROME_BROWSER_MEDIA_ROUTER_RECEIVER_PRESENTATION_SERVICE_DELEGATE_IMPL_H_
+
+#include <map>
+#include <memory>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/observer_list.h"
+
+#include "chrome/browser/media/router/offscreen_presentation_manager.h"
+#include "chrome/browser/media/router/offscreen_presentation_manager_factory.h"
+#include "chrome/browser/media/router/render_frame_host_id.h"
+#include "content/public/browser/presentation_service_delegate.h"
+#include "content/public/browser/web_contents_user_data.h"
+
+namespace content {
+class RenderFrameHost;
+class WebContents;
+struct PresentationSessionInfo;
+struct PresentationSessionMessage;
+}  // namespace content
+
+namespace media_router {
+
+// Implements the receiver side of presentation API for offscreen presentations.

[mark a. foltz, 2016/11/08 23:40:52]

nit: Presentation

[zhaobin, 2016/11/10 04:14:00]

Done.

+// Created under the offscreen tab WebContents when the tab is created for an

[mark a. foltz, 2016/11/08 23:40:52]

There's currently no "tab" or visual indicator in the tab strip for the
offscreen presentation, so I would just say:

Created with the offscreen WebContents for an offscreen presentation.

[zhaobin, 2016/11/10 04:14:00]

Done.

+// offscreen presentation. Each instance is tied to a single offscreen
+// presentation whose ID is given during construction. As such, the receiver
+// APIs are contextual with the offscreen presentation.
+// Only the main frame of the offscreen tab is allowed to make receiver

[mark a. foltz, 2016/11/08 23:40:52]

offscreen WebContents

[zhaobin, 2016/11/10 04:14:00]

Done.

+// Presentation API requests; requests made from any other frame will be
+// rejected.
+class ReceiverPresentationServiceDelegateImpl
+    : public content::WebContentsUserData<
+          ReceiverPresentationServiceDelegateImpl>,
+      public content::ReceiverPresentationServiceDelegate {
+ public:
+  // Creates an instance of ReceiverPresentationServiceDelegateImpl under
+  // |web_contents| and registers it as the receiver of the offscreen
+  // presentation |presentation_id| with OffscreenPresentationManager.
+  // No-op if a ReceiverPresentationServiceDelegateImpl instance already
+  // exists under |web_contents|.

[mark a. foltz, 2016/11/08 23:40:51]

Document that this does not take ownership of |web_contents|.

[zhaobin, 2016/11/10 04:14:00]

Done.

+  static void CreateForWebContents(content::WebContents* web_contents,
+                                   const std::string& presentation_id);
+
+  ~ReceiverPresentationServiceDelegateImpl() override;
+
+  // content::PresentationServiceDelegateBase implementation.
+  void AddObserver(
+      int render_process_id,
+      int render_frame_id,
+      content::PresentationServiceDelegateBase::Observer* observer) override;
+  void RemoveObserver(int render_process_id, int render_frame_id) override;
+  void Reset(int render_process_id, int render_frame_id) override;
+
+  // content::ReceiverPresentationServiceDelegate implementation.
+  void RegisterReceiverConnectionAvailableCallback(
+      const content::ReceiverConnectionAvailableCallback&
+          receiver_available_callback) override;
+
+ private:
+  friend class content::WebContentsUserData<
+      ReceiverPresentationServiceDelegateImpl>;
+
+  ReceiverPresentationServiceDelegateImpl(content::WebContents* web_contents,
+                                          const std::string& presentation_id);
+
+  // Reference to the WebContents that owns this instance.
+  content::WebContents* const web_contents_;

[mark a. foltz, 2016/11/08 23:40:52]

There is a risk you will call into |web_contents_| during the WebContents dtor. 
Are you sure that WebContentsUserData are all destroyed before WebContents?

[zhaobin, 2016/11/10 04:14:00]

Did some manual tests, ~ReceiverPSDImpl() always happens before WebContents
dtor, e.g. call window.close() on receiver page. ReceiverPSDImpl is
CreatedForWebContents(), it seems to be a member of webContents, and WebContents
will take care of the destruction order (not sure though)?

+
+  const std::string presentation_id_;
+  OffscreenPresentationManager* const offscreen_presentation_manager_;
+  std::map<RenderFrameHostId,
+           content::PresentationServiceDelegateBase::Observer*>
+      observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(ReceiverPresentationServiceDelegateImpl);
+};
+
+}  // namespace media_router
+
+#endif  // CHROME_BROWSER_MEDIA_ROUTER_RECEIVER_PRESENTATION_SERVICE_DELEGATE_IMPL_H_