[Presentation API] 1-UA presentation support + presenter APIs.

chrome/browser/extensions/api/tab_capture/offscreen_tab.cc

Index: chrome/browser/extensions/api/tab_capture/offscreen_tab.cc
diff --git a/chrome/browser/extensions/api/tab_capture/offscreen_tab.cc b/chrome/browser/extensions/api/tab_capture/offscreen_tab.cc
index ddc31cf18549dfeffde8653079308719039f378f..3c2c99fe88b6b8392b467460de25f144e124086f 100644
--- a/chrome/browser/extensions/api/tab_capture/offscreen_tab.cc
+++ b/chrome/browser/extensions/api/tab_capture/offscreen_tab.cc
@@ -9,6 +9,7 @@
 #include "base/bind.h"
 #include "base/macros.h"
 #include "chrome/browser/extensions/api/tab_capture/tab_capture_registry.h"
+#include "chrome/browser/media/router/receiver_presentation_service_delegate_impl.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/ui/web_contents_sizer.h"
 #include "content/public/browser/render_widget_host_view.h"
@@ -104,11 +105,10 @@ void OffscreenTab::Start(const GURL& start_url,
   // automatically unmuted, but will be captured into the MediaStream.
   offscreen_tab_web_contents_->SetAudioMuted(true);
 
-  // TODO(imcheng): If |optional_presentation_id| is not empty, register it with
-  // the PresentationRouter.  http://crbug.com/513859
   if (!optional_presentation_id.empty()) {
-    NOTIMPLEMENTED()
-        << "Register with PresentationRouter, id=" << optional_presentation_id;
+    // Register the offscreen tab as the receiver of the offscreen presentation.
+    media_router::ReceiverPresentationServiceDelegateImpl::CreateForWebContents(
+        offscreen_tab_web_contents_.get(), optional_presentation_id);
   }
 
   // Navigate to the initial URL.