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

chrome/browser/media/router/receiver_presentation_service_delegate_impl.cc

+// 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.
+
+#include "chrome/browser/media/router/receiver_presentation_service_delegate_impl.h"
+
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_process_host.h"
+#include "url/gurl.h"
+
+DEFINE_WEB_CONTENTS_USER_DATA_KEY(
+    media_router::ReceiverPresentationServiceDelegateImpl);
+
+using content::RenderFrameHost;
+
+namespace media_router {
+
+// static
+void ReceiverPresentationServiceDelegateImpl::CreateForWebContents(
+    content::WebContents* web_contents,
+    const std::string& presentation_id) {
+  DCHECK(web_contents);
+
+  if (FromWebContents(web_contents))
+    return;
+
+  web_contents->SetUserData(UserDataKey(),
+                            new ReceiverPresentationServiceDelegateImpl(
+                                web_contents, presentation_id));
+}
+
+ReceiverPresentationServiceDelegateImpl::
+    ~ReceiverPresentationServiceDelegateImpl() {
+  for (auto& observer_pair : observers_)
+    observer_pair.second->OnDelegateDestroyed();
+}
+
+void ReceiverPresentationServiceDelegateImpl::AddObserver(

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

Can AddObserver/RemoveObserver be moved into PresentationServiceDelegateBase? 
The API only depends on content:: and the implementation should be identical
across controller and receiver.

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

Done.

+    int render_process_id,
+    int render_frame_id,
+    content::PresentationServiceDelegateBase::Observer* observer) {
+  DCHECK(observer);
+
+  RenderFrameHostId rfh_id(render_process_id, render_frame_id);
+  DCHECK(!base::ContainsKey(observers_, rfh_id));
+  observers_[rfh_id] = observer;

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

I am not sure why the map is needed.  Is it important that there is only one
observer per render_frame_id/render_host_id?  When would there be more than one
observer registered for the same render frame host?  It seems like that would be
a bug given how it's used in PresentationServiceImpl.

Also, what guarantees that |observer| outlives |this| here?  I'm assuming it's
because |observer| is implemented by PresentationServiceImpl which also owns the
delegate.

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

multiple PSImpl objects may reference to the same PSDImpl object. Need to keep a
map for all PSImpl referencing current PSDImpl object. Since PSImpl does not own
PSDImpl obj, PSDImpl obj might be destroyed earlier than PSImpl, and must notify
all PSImpl referencing it.

~PSImpl() will remove itself from PSDImpl's observer list. |observer| should
always be valid.

+}
+
+void ReceiverPresentationServiceDelegateImpl::RemoveObserver(
+    int render_process_id,
+    int render_frame_id) {
+  observers_.erase(RenderFrameHostId(render_process_id, render_frame_id));
+}
+
+void ReceiverPresentationServiceDelegateImpl::Reset(int render_process_id,
+                                                    int render_frame_id) {
+  DVLOG(2) << __FUNCTION__ << render_process_id << ", " << render_frame_id;
+  offscreen_presentation_manager_->OnOffscreenPresentationReceiverTerminated(
+      presentation_id_);
+}
+
+ReceiverPresentationServiceDelegateImpl::
+    ReceiverPresentationServiceDelegateImpl(content::WebContents* web_contents,
+                                            const std::string& presentation_id)
+    : web_contents_(web_contents),
+      presentation_id_(presentation_id),
+      offscreen_presentation_manager_(
+          OffscreenPresentationManagerFactory::
+              GetOrCreateForReceiverBrowserContext(web_contents_)) {
+  DCHECK(web_contents_);
+  DCHECK(!presentation_id.empty());
+  DCHECK(offscreen_presentation_manager_);
+}
+
+void ReceiverPresentationServiceDelegateImpl::
+    RegisterReceiverConnectionAvailableCallback(
+        const content::ReceiverConnectionAvailableCallback&
+            receiver_available_callback) {
+  offscreen_presentation_manager_->OnOffscreenPresentationReceiverCreated(
+      presentation_id_, web_contents_->GetLastCommittedURL(),
+      receiver_available_callback);
+}
+
+}  // namespace media_router