bluetooth: Detect and fix incorrect thread usage of BluetoothDispatcherHost.

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 fc76c3220ad0f89226b4a4357c0aee012d654821..3d1007b98fa453cd4651550e7d31be762e310347 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
@@ -11,6 +11,7 @@ import android.os.Build;
 import android.os.ParcelUuid;
 
 import org.chromium.base.Log;
+import org.chromium.base.ThreadUtils;
 import org.chromium.base.annotations.CalledByNative;
 import org.chromium.base.annotations.JNINamespace;
 
@@ -133,14 +134,19 @@ final class ChromeBluetoothDevice {
     // Implements callbacks related to a GATT connection.
     private class BluetoothGattCallbackImpl extends Wrappers.BluetoothGattCallbackWrapper {
         @Override
-        public void onConnectionStateChange(int status, int newState) {
+        public void onConnectionStateChange(final int status, final int newState) {
             Log.i(TAG, "onConnectionStateChange status:%d newState:%s", status,
                     (newState == android.bluetooth.BluetoothProfile.STATE_CONNECTED)
                             ? "Connected"
                             : "Disconnected");
             if (mNativeBluetoothDeviceAndroid != 0) {

[qinmin, 2015/10/05 18:38:54]

this is not threadsafe, see my comments below

[scheib, 2015/10/05 21:01:33]

Done.

-                nativeOnConnectionStateChange(mNativeBluetoothDeviceAndroid, status,
-                        newState == android.bluetooth.BluetoothProfile.STATE_CONNECTED);
+                ThreadUtils.runOnUiThread(new Runnable() {
+                    @Override
+                    public void run() {
+                        nativeOnConnectionStateChange(mNativeBluetoothDeviceAndroid, status,

[qinmin, 2015/10/05 18:38:54]

when this gets called, mNativeBluetoothDeviceAndroid could become 0. So what
about doing the if (mNativeBluetoothDeviceAndroid!=0) here instead of in
onConnectionStateChange()?

[scheib, 2015/10/05 21:01:33]

Done.

+                                newState == android.bluetooth.BluetoothProfile.STATE_CONNECTED);
+                    }
+                });
             }
         }
     }