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

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index bb2aa36451ff92f62c614f1c5d4a24840ce6a60e..5019ed0a0a4cc5622b521b4cfab12bd5d878086a 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -305,6 +305,7 @@
 #if defined(ENABLE_MEDIA_ROUTER)
 #include "chrome/browser/media/router/media_router_feature.h"
 #include "chrome/browser/media/router/presentation_service_delegate_impl.h"
+#include "chrome/browser/media/router/receiver_presentation_service_delegate_impl.h"
 #endif
 
 #if defined(ENABLE_WAYLAND_SERVER)
@@ -2829,6 +2830,13 @@ ChromeContentBrowserClient::GetPresentationServiceDelegate(
       content::WebContents* web_contents) {
 #if defined(ENABLE_MEDIA_ROUTER)
   if (media_router::MediaRouterEnabled(web_contents->GetBrowserContext())) {
+    // ReceiverPresentationServiceDelegateImpl are for WebContents created for
+    // offscreen presentations. The WebContents is from an incognito profile.
+    if (auto* impl = media_router::ReceiverPresentationServiceDelegateImpl::
+            FromWebContents(web_contents)) {
+      DCHECK(web_contents->GetBrowserContext()->IsOffTheRecord());
+      return impl;
+    }
     return media_router::PresentationServiceDelegateImpl::
         GetOrCreateForWebContents(web_contents);
   }