Add a permission for controlling wifi display.

Change-Id: I321b6c1a0223e0c3d5df04fde7a13ab91c08c7bc
diff --git a/media/libmediaplayerservice/MediaPlayerService.cpp b/media/libmediaplayerservice/MediaPlayerService.cpp
index 6b57c48..1be4edf 100644
--- a/media/libmediaplayerservice/MediaPlayerService.cpp
+++ b/media/libmediaplayerservice/MediaPlayerService.cpp
@@ -283,10 +283,19 @@
 
 sp<IRemoteDisplay> MediaPlayerService::listenForRemoteDisplay(
         const sp<IRemoteDisplayClient>& client, const String8& iface) {
+    if (!checkPermission("android.permission.CONTROL_WIFI_DISPLAY")) {
+        return NULL;
+    }
+
     return new RemoteDisplay(client, iface.string());
 }
 
+// TODO: delete this method
 status_t MediaPlayerService::enableRemoteDisplay(const char *iface) {
+    if (!checkPermission("android.permission.CONTROL_WIFI_DISPLAY")) {
+        return PERMISSION_DENIED;
+    }
+
     Mutex::Autolock autoLock(mLock);
 
     if (iface != NULL) {