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

chrome/browser/chrome_content_browser_client.cc

 // Copyright (c) 2012 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/chrome_content_browser_client.h"
 
 #include <map>
 #include <set>
 #include <utility>
 #include <vector>
@@ skipping 326 matching lines @@
 #endif
 
 #if BUILDFLAG(ENABLE_WEBRTC)
 #include "chrome/browser/media/audio_debug_recordings_handler.h"
 #include "chrome/browser/media/webrtc/webrtc_logging_handler_host.h"
 #endif
 
 #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  // defined(ENABLE_MEDIA_ROUTER)
 
 #if BUILDFLAG(ENABLE_MEDIA_REMOTING) && defined(ENABLE_MEDIA_ROUTER)
 #include "chrome/browser/media/cast_remoting_connector.h"
 #endif
 
 
 #if defined(ENABLE_WAYLAND_SERVER)
 #include "chrome/browser/chrome_browser_main_extra_parts_exo.h"
 #endif
@@ skipping 2769 matching lines @@
       params.url,
       params.transition);
   FillNavigateParamsFromOpenURLParams(&nav_params, params);
   nav_params.user_gesture = params.user_gesture;
 
   Navigate(&nav_params);
   callback.Run(nav_params.target_contents);
 #endif
 }
 
-content::PresentationServiceDelegate*
-ChromeContentBrowserClient::GetPresentationServiceDelegate(
-      content::WebContents* web_contents) {
+content::ControllerPresentationServiceDelegate*
+ChromeContentBrowserClient::GetControllerPresentationServiceDelegate(
+    content::WebContents* web_contents) {
 #if defined(ENABLE_MEDIA_ROUTER)
   if (media_router::MediaRouterEnabled(web_contents->GetBrowserContext())) {
     return media_router::PresentationServiceDelegateImpl::
         GetOrCreateForWebContents(web_contents);
   }
 #endif  // defined(ENABLE_MEDIA_ROUTER)
   return nullptr;
 }
 
+content::ReceiverPresentationServiceDelegate*
+ChromeContentBrowserClient::GetReceiverPresentationServiceDelegate(
+    content::WebContents* web_contents) {
+#if defined(ENABLE_MEDIA_ROUTER)
+  if (media_router::MediaRouterEnabled(web_contents->GetBrowserContext())) {
+    // ReceiverPresentationServiceDelegateImpl exists only for WebContents
+    // created for offscreen presentations. The WebContents must belong to
+    // an incognito profile.
+    auto* impl =
+        media_router::ReceiverPresentationServiceDelegateImpl::FromWebContents(
+            web_contents);
+    if (impl && web_contents->GetBrowserContext()->IsOffTheRecord())

[dcheng, 2017/01/06 11:54:22]

I would expect the IsOffTheRecord() bit to a be a DCHECK(): we shouldn't be
creating it for a  non-OTR browser context at all, should we?

Which means this can just be simplified to:

auto* impl =
media_router::ReceiverPresentationServiceDelegateImpl::FromWebContents(web_contents);
DCHECK(web_contents->GetBrowserContext()->IsOffTheRecord());
return impl;

[zhaobin, 2017/01/10 01:39:17]

Mark suggests not using DCHECK in patch set 1:

mark a. foltz 2016/11/08 23:40:51
API design opinion:

This API is part of content/browser and it's a little weird to have a method
that will DCHECK for some WebContents.  If the caller passes a WebContents* that
cannot be a receiver, I would just return nullptr instead of DCHECK(), and the
caller can check the return value if it expects it to be valid.

[dcheng, 2017/01/10 06:46:58]

It's not really that weird, IMO. If we shouldn't have to handle "impossible
cases" (i.e. the impossible case is developer error), then it's better to DCHECK
rather than fail silently.

As an example, consider base::StringValue. base::StringValue expects to only
hold Unicode strings. If a non-UTF8 std::string is passed, we don't provide a
way to gracefully fail -- we just DCHECK, because the developer did something
wrong.

Unless there's a good reason to do otherwise, I think we should stick to that
pattern here.

[zhaobin, 2017/01/10 21:49:54]

Done.

+      return impl;
+  }
+#endif  // defined(ENABLE_MEDIA_ROUTER)
+  return nullptr;
+}
+
 void ChromeContentBrowserClient::RecordURLMetric(const std::string& metric,
                                                  const GURL& url) {
   if (url.is_valid()) {
     rappor::SampleDomainAndRegistryFromGURL(g_browser_process->rappor_service(),
                                             metric, url);
   }
 }
 
 ScopedVector<content::NavigationThrottle>
 ChromeContentBrowserClient::CreateThrottlesForNavigation(
@@ skipping 189 matching lines @@
           GetBrowserSchedulerWorkerPoolParamsFromVariations();
   *index_to_traits_callback = base::Bind(&task_scheduler_util::initialization::
                                              BrowserWorkerPoolIndexForTraits);
 }
 
 void ChromeContentBrowserClient::
     PerformExperimentalTaskSchedulerRedirections() {
   task_scheduler_util::variations::
       MaybePerformBrowserTaskSchedulerRedirection();
 }