Bug 881194 - [Bluetooth] Support AT+CHLD=3 in dom bluetooth. When "AT+CHLD=3" is received from a hands-free device, notify the Dialer app to "Add a held call to the conversation". r=echou

dom/bluetooth/bluez/BluetoothHfpManager.cpp

@@ -832,7 +832,7 @@ BluetoothHfpManager::ReceiveSocketData(BluetoothSocket* aSocket,
     mCurrentVgm = vgm;
 #ifdef MOZ_B2G_RIL
   } else if (msg.Find("AT+CHLD=?") != -1) {
-    SendLine("+CHLD: (0,1,2)");
+    SendLine("+CHLD: (0,1,2,3)");
   } else if (msg.Find("AT+CHLD=") != -1) {
     ParseAtCommand(msg, 8, atCommandValues);
 
@@ -849,9 +849,10 @@ BluetoothHfpManager::ReceiveSocketData(BluetoothSocket* aSocket,
      *             waiting) call
      * AT+CHLD=2 - Places active calls on hold and accepts the other (held
      *             or waiting) call
+     * AT+CHLD=3 - Adds a held call to the conversation.
      *
      * The following cases are NOT supported yet:
-     * AT+CHLD=1<idx>, AT+CHLD=2<idx>, AT+CHLD=3, AT+CHLD=4
+     * AT+CHLD=1<idx>, AT+CHLD=2<idx>, AT+CHLD=4
      * Please see 4.33.2 in Bluetooth hands-free profile 1.6 for more
      * information.
      */
@@ -860,7 +861,7 @@ BluetoothHfpManager::ReceiveSocketData(BluetoothSocket* aSocket,
     if (atCommandValues[0].Length() > 1) {
       BT_WARNING("No index should be included in command [AT+CHLD]");
       valid = false;
-    } else if (chld == '3' || chld == '4') {
+    } else if (chld == '4') {
       BT_WARNING("The value of command [AT+CHLD] is not supported");
       valid = false;
     } else if (chld == '0') {
@@ -872,6 +873,8 @@ BluetoothHfpManager::ReceiveSocketData(BluetoothSocket* aSocket,
       NotifyDialer(NS_LITERAL_STRING("CHLD=1"));
     } else if (chld == '2') {
       NotifyDialer(NS_LITERAL_STRING("CHLD=2"));
+    } else if (chld == '3') {
+      NotifyDialer(NS_LITERAL_STRING("CHLD=3"));
     } else {
       BT_WARNING("Wrong value of command [AT+CHLD]");
       valid = false;