Merge "Catch SecurityException within LatencyTracker" into udc-dev

     * using a single static object.

     */

    @VisibleForTesting

    @RequiresPermission(Manifest.permission.READ_DEVICE_CONFIG)

    public void startListeningForLatencyTrackerConfigChanges() {

        final Context context = ActivityThread.currentApplication();

        if (context != null

                && context.checkCallingOrSelfPermission(READ_DEVICE_CONFIG) == PERMISSION_GRANTED) {

            // Post initialization to the background in case we're running on the main thread.

            BackgroundThread.getHandler().post(() -> this.updateProperties(

                    DeviceConfig.getProperties(NAMESPACE_LATENCY_TRACKER)));

            DeviceConfig.addOnPropertiesChangedListener(NAMESPACE_LATENCY_TRACKER,

                    BackgroundThread.getExecutor(), mOnPropertiesChangedListener);

        } else {

            if (DEBUG) {

        if (context == null) {

                    Log.d(TAG, "No application for " + ActivityThread.currentActivityThread());

                } else {

            if (DEBUG) {

                Log.d(TAG, "No application for package: " + ActivityThread.currentPackageName());

            }

            return;

        }

        if (context.checkCallingOrSelfPermission(READ_DEVICE_CONFIG) != PERMISSION_GRANTED) {

            if (DEBUG) {

                synchronized (mLock) {

                    Log.d(TAG, "Initialized the LatencyTracker."

                            + " (No READ_DEVICE_CONFIG permission to change configs)"

                            + " enabled=" + mEnabled + ", package=" + context.getPackageName());

                }

            }

            return;

        }

        }

        // Post initialization to the background in case we're running on the main thread.

        BackgroundThread.getHandler().post(() -> {

            try {

                this.updateProperties(

                        DeviceConfig.getProperties(NAMESPACE_LATENCY_TRACKER));

                DeviceConfig.addOnPropertiesChangedListener(NAMESPACE_LATENCY_TRACKER,

                        BackgroundThread.getExecutor(), mOnPropertiesChangedListener);

            } catch (SecurityException ex) {

                // In case of running tests that the main thread passes the check,

                // but the background thread doesn't have necessary permissions.

                // Swallow it since it's ok to ignore device config changes in the tests.

                Log.d(TAG, "Can't get properties: READ_DEVICE_CONFIG granted="

                        + context.checkCallingOrSelfPermission(READ_DEVICE_CONFIG)

                        + ", package=" + context.getPackageName());

            }

        });

    }

    /**