Call BluetoothGatt#close() after disconnecting

device/bluetooth/android/java/src/org/chromium/device/bluetooth/ChromeBluetoothDevice.java

Index: device/bluetooth/android/java/src/org/chromium/device/bluetooth/ChromeBluetoothDevice.java
diff --git a/device/bluetooth/android/java/src/org/chromium/device/bluetooth/ChromeBluetoothDevice.java b/device/bluetooth/android/java/src/org/chromium/device/bluetooth/ChromeBluetoothDevice.java
index 6b163d828a2969461823ec1590fbb9d4d8e4a630..88e290f41d7fb6d751fbce861735f768dfecd92a 100644
--- a/device/bluetooth/android/java/src/org/chromium/device/bluetooth/ChromeBluetoothDevice.java
+++ b/device/bluetooth/android/java/src/org/chromium/device/bluetooth/ChromeBluetoothDevice.java
@@ -59,7 +59,10 @@ final class ChromeBluetoothDevice {
      */
     @CalledByNative
     private void onBluetoothDeviceAndroidDestruction() {
-        disconnectGatt();
+        if (mBluetoothGatt != null) {
+            mBluetoothGatt.close();
+            mBluetoothGatt = null;
+        }
         mNativeBluetoothDeviceAndroid = 0;
     }
 
@@ -119,6 +122,9 @@ final class ChromeBluetoothDevice {
     @CalledByNative
     private void createGattConnectionImpl(Context context) {
         Log.i(TAG, "connectGatt");
+
+        if (mBluetoothGatt != null) mBluetoothGatt.close();
+
         // autoConnect set to false as under experimentation using autoConnect failed to complete
         // connections.
         mBluetoothGatt =
@@ -148,6 +154,11 @@ final class ChromeBluetoothDevice {
                             : "Disconnected");
             if (newState == android.bluetooth.BluetoothProfile.STATE_CONNECTED) {
                 mBluetoothGatt.discoverServices();
+            } else if (newState == android.bluetooth.BluetoothProfile.STATE_DISCONNECTED) {
+                if (mBluetoothGatt != null) {
+                    mBluetoothGatt.close();
+                    mBluetoothGatt = null;
+                }
             }
             ThreadUtils.runOnUiThread(new Runnable() {
                 @Override