[MediaRouter] PresentationServiceDelegateImpl cleanup.

content/browser/presentation/presentation_service_impl.cc

 // Copyright 2015 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 "content/browser/presentation/presentation_service_impl.h"
 
 #include <stddef.h>
 #include <stdint.h>
 #include <algorithm>
 #include <utility>
@@ skipping 105 matching lines @@
 
   if (receiver_delegate_) {
     receiver_delegate_->RegisterReceiverConnectionAvailableCallback(
         base::Bind(&PresentationServiceImpl::OnReceiverConnectionAvailable,
                    weak_factory_.GetWeakPtr()));
   }
 }
 
 void PresentationServiceImpl::ListenForScreenAvailability(const GURL& url) {
   DVLOG(2) << "ListenForScreenAvailability " << url.spec();
-  if (!controller_delegate_) {
+  if (!controller_delegate_ || !url.is_valid()) {
     client_->OnScreenAvailabilityUpdated(
         url, blink::mojom::ScreenAvailability::UNAVAILABLE);
     return;
   }
 
   if (screen_availability_listeners_.count(url))
     return;
 
   std::unique_ptr<ScreenAvailabilityListenerImpl> listener(
       new ScreenAvailabilityListenerImpl(url, this));
@@ skipping 315 matching lines @@
     const PresentationInfo& connection) {
   DCHECK(client_.get());
   client_->OnDefaultPresentationStarted(connection);
   ListenForConnectionStateChange(connection);
 }
 
 PresentationServiceImpl::ScreenAvailabilityListenerImpl::
     ScreenAvailabilityListenerImpl(const GURL& availability_url,
                                    PresentationServiceImpl* service)
     : availability_url_(availability_url), service_(service) {
+  DCHECK(availability_url_.is_valid());
   DCHECK(service_);
   DCHECK(service_->client_.get());
 }
 
 PresentationServiceImpl::ScreenAvailabilityListenerImpl::
-~ScreenAvailabilityListenerImpl() {
-}
+    ~ScreenAvailabilityListenerImpl() = default;
 
 GURL PresentationServiceImpl::ScreenAvailabilityListenerImpl::
     GetAvailabilityUrl() const {
   return availability_url_;
 }
 
 void PresentationServiceImpl::ScreenAvailabilityListenerImpl::
     OnScreenAvailabilityChanged(blink::mojom::ScreenAvailability availability) {
   service_->client_->OnScreenAvailabilityUpdated(availability_url_,
                                                  availability);
@@ skipping 10 matching lines @@
 }
 
 void PresentationServiceImpl::NewPresentationCallbackWrapper::Run(
     const base::Optional<PresentationInfo>& presentation_info,
     const base::Optional<PresentationError>& error) {
   DCHECK(!callback_.is_null());
   std::move(callback_).Run(presentation_info, error);
 }
 
 }  // namespace content