[Chromecast] Use separate endpoint for audio backend unittests

Bug: internal b/151990838
Change-Id: I3b852cb23f5320f69c75a9ffbdd8cdc58fecff2f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2134195
Commit-Queue: Kenneth MacKay <kmackay@chromium.org>
Reviewed-by: Yuchen Liu <yucliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756324}

chromecast/BUILD.gn

@@ -128,7 +128,11 @@ cast_test_group("cast_tests") {
       test_name = "cast_audio_backend_unittests"
 
       # --test-launcher-jobs=1 => so mixer service receiver can bind.
-      args = [ "--test-launcher-jobs=1" ]
+      args = [
+        "--test-launcher-jobs=1",
+        "--mixer-service-endpoint=/tmp/cast_audio_backend_unittest-mixer",
+        "--mixer-service-port=12855",
+      ]
     }
     filters += [ cast_audio_backend_unittests_filter ]
   }

chromecast/base/chromecast_switches.cc

@@ -185,11 +185,14 @@ const char kBackGestureHorizontalThreshold[] =
 // Whether to enable detection and dispatch of a 'drag from the top' gesture.
 const char kEnableTopDragGesture[] = "enable-top-drag-gesture";
 
-// Endpoint that the mixer service listens on. On Linux/Android, this is a
-// path for a UNIX domain socket (default is /tmp/mixer-service). On other
-// platforms, this is a TCP port to listen on (on localhost) (default 12854).
+// Endpoint that the mixer service listens on. This is a path for a UNIX domain
+// socket (default is /tmp/mixer-service).
 const char kMixerServiceEndpoint[] = "mixer-service-endpoint";
 
+// TCP port that the mixer service listens on on non-Linux platforms.
+// (default 12854).
+const char kMixerServicePort[] = "mixer-service-port";
+
 extern const char kCastMemoryPressureCriticalFraction[] =
     "memory-pressure-critical-fraction";
 extern const char kCastMemoryPressureModerateFraction[] =

chromecast/base/chromecast_switches.h

@@ -89,6 +89,8 @@ extern const char kEnableTopDragGesture[];
 extern const char kCastAppBackgroundColor[];
 
 extern const char kMixerServiceEndpoint[];
+extern const char kMixerServicePort[];
+
 extern const char kCastMemoryPressureCriticalFraction[];
 extern const char kCastMemoryPressureModerateFraction[];
 

chromecast/media/audio/mixer_service/mixer_connection.cc

@@ -55,7 +55,7 @@ void MixerConnection::Connect() {
   if (path.empty()) {
     path = kDefaultUnixDomainSocketPath;
   }
-  int port = GetSwitchValueNonNegativeInt(switches::kMixerServiceEndpoint,
+  int port = GetSwitchValueNonNegativeInt(switches::kMixerServicePort,
                                           kDefaultTcpPort);
   connecting_socket_ = AudioSocketService::Connect(path, port);
 

chromecast/media/audio/mixer_service/receiver/receiver.cc

@@ -128,7 +128,7 @@ Receiver::Receiver()
     : task_runner_(base::SequencedTaskRunnerHandle::Get()),
       socket_service_(
           GetEndpoint(),
-          GetSwitchValueNonNegativeInt(switches::kMixerServiceEndpoint,
+          GetSwitchValueNonNegativeInt(switches::kMixerServicePort,
                                        mixer_service::kDefaultTcpPort),
           kMaxAcceptLoop,
           this),