[Native Cast MRP] Presentation connection for site-initiated mirroring

This fixes a regression relative to the extension MRP where we were
establishing a presentation connection only if a client ID is set.
If mirroring is initiated by a site with cast:0F5096E8 there is no
client ID but we still need a presentation connection.

Bug: 1114891, b/163366468
Change-Id: Ib66768c52851bb87aba307775d917b81bf669572
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2347890
Commit-Queue: Takumi Fujimoto <takumif@chromium.org>
Reviewed-by: mark a. foltz <mfoltz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#796940}

chrome/browser/media/router/providers/cast/cast_activity_manager.cc

@@ -193,7 +193,7 @@ void CastActivityManager::DoLaunchSession(DoLaunchSessionParams params) {
           ? AddMirroringActivity(route, app_id, tab_id, sink.cast_data())
           : AddAppActivity(route, app_id);
   const std::string& client_id = cast_source.client_id();
-  if (!client_id.empty()) {
+  if (MediaSource(cast_source.source_id()).IsCastPresentationUrl()) {
     presentation_connection =
         activity_ptr->AddClient(cast_source, params.origin, tab_id);
     activity_ptr->SendMessageToClient(

chrome/browser/media/router/providers/cast/cast_activity_manager_unittest.cc

@@ -28,6 +28,7 @@
 #include "chrome/browser/media/router/test/mock_logger.h"
 #include "chrome/browser/media/router/test/mock_mojo_media_router.h"
 #include "chrome/browser/media/router/test/test_helper.h"
+#include "chrome/common/media_router/media_source.h"
 #include "chrome/common/media_router/test/test_helper.h"
 #include "components/cast_channel/cast_test_util.h"
 #include "content/public/browser/browser_task_traits.h"
@@ -56,6 +57,7 @@ namespace media_router {
 namespace {
 constexpr int kChannelId = 42;
 constexpr int kChannelId2 = 43;
+constexpr char kClientId[] = "theClientId";
 constexpr char kOrigin[] = "https://google.com";
 constexpr int kTabId = 1;
 constexpr int kTabId2 = 2;
@@ -76,9 +78,10 @@ constexpr char kPresentationId[] = "presentationId";
 constexpr char kPresentationId2[] = "presentationId2";
 
 std::string MakeSourceId(const std::string& app_id = kAppId1,
-                         const std::string& app_params = "") {
+                         const std::string& app_params = "",
+                         const std::string& client_id = kClientId) {
   return base::StrCat(
-      {"cast:", app_id, "?clientId=theClientId&appParams=", app_params});
+      {"cast:", app_id, "?clientId=", client_id, "&appParams=", app_params});
 }
 
 base::Value MakeReceiverStatus(const std::string& app_id,
@@ -207,6 +210,7 @@ class CastActivityManagerTest : public testing::Test,
       media_router::RouteRequestResult::ResultCode) {
     ASSERT_TRUE(route);
     route_ = std::make_unique<MediaRoute>(*route);
+    presentation_connections_ = std::move(presentation_connections);
   }
 
   void ExpectLaunchSessionFailure(
@@ -219,7 +223,8 @@ class CastActivityManagerTest : public testing::Test,
   }
 
   void CallLaunchSession(const std::string& app_id = kAppId1,
-                         const std::string& app_params = "") {
+                         const std::string& app_params = "",
+                         const std::string& client_id = kClientId) {
     // MediaRouter is notified of new route.
     ExpectSingleRouteUpdate();
 
@@ -234,8 +239,8 @@ class CastActivityManagerTest : public testing::Test,
           launch_session_callback_ = std::move(callback);
         }));
 
-    auto source =
-        CastMediaSource::FromMediaSourceId(MakeSourceId(app_id, app_params));
+    auto source = CastMediaSource::FromMediaSourceId(
+        MakeSourceId(app_id, app_params, client_id));
     ASSERT_TRUE(source);
 
     cast_activity_callback_ =
@@ -403,6 +408,7 @@ class CastActivityManagerTest : public testing::Test,
   base::Optional<MediaRoute> updated_route_;
   cast_channel::ResultCallback stop_session_callback_;
   MockLogger logger_;
+  mojom::RoutePresentationConnectionPtr presentation_connections_;
 };
 
 TEST_F(CastActivityManagerTest, LaunchCastAppSession) {
@@ -420,6 +426,14 @@ TEST_F(CastActivityManagerTest, LaunchMirroringSession) {
   EXPECT_EQ(RouteControllerType::kMirroring, route_->controller_type());
 }
 
+TEST_F(CastActivityManagerTest, LaunchSiteInitiatedMirroringSession) {
+  // For a session initiated by a website with the mirroring source we should be
+  // establishing a presentation connection, even if the client ID isn't set.
+  CallLaunchSession(kCastStreamingAppId, /*app_params*/ "", /*client_id*/ "");
+  EXPECT_FALSE(presentation_connections_.is_null());
+  EXPECT_EQ(RouteControllerType::kMirroring, route_->controller_type());
+}
+
 TEST_F(CastActivityManagerTest, MirroringSessionStopped) {
   CallLaunchSession(kCastStreamingAppId);
   auto response = GetSuccessLaunchResponse();

chrome/browser/media/router/providers/cast/mirroring_activity.cc

@@ -209,6 +209,16 @@ void MirroringActivity::Send(mirroring::mojom::CastMessagePtr message) {
                      weak_ptr_factory_.GetWeakPtr(), route().media_route_id()));
 }
 
+void MirroringActivity::SendMessageToClient(
+    const std::string& client_id,
+    blink::mojom::PresentationConnectionMessagePtr message) {
+  // A client exists if this is a site-initiated mirroring session. Given client
+  // ID is a Cast SDK concept, the client may not have an ID if it joined by
+  // directly using the Presentation API, and we wouldn't be able to distinguish
+  // them. We also do not expect the mirroring receiver to send any messages, so
+  // we drop them.
+}
+
 void MirroringActivity::OnAppMessage(
     const cast::channel::CastMessage& message) {
   if (!route_.is_local())

chrome/browser/media/router/providers/cast/mirroring_activity.h

@@ -62,6 +62,9 @@ class MirroringActivity : public CastActivity,
   void Send(mirroring::mojom::CastMessagePtr message) override;
 
   // CastActivity implementation
+  void SendMessageToClient(
+      const std::string& client_id,
+      blink::mojom::PresentationConnectionMessagePtr message) override;
   void OnAppMessage(const cast::channel::CastMessage& message) override;
   void OnInternalMessage(const cast_channel::InternalMessage& message) override;