private boolean newSessionInternal(ICustomTabsCallback callback, PendingIntent sessionId) {
            final CustomTabsSessionToken sessionToken =
                    new CustomTabsSessionToken(callback, sessionId);
            try {
                DeathRecipient deathRecipient = () -> cleanUpSession(sessionToken);
                synchronized (mDeathRecipientMap) {
                    callback.asBinder().linkToDeath(deathRecipient, 0);
                    mDeathRecipientMap.put(callback.asBinder(), deathRecipient);
                }
                return CustomTabsService.this.newSession(sessionToken);
            } catch (RemoteException e) {
                return false;
            }
        }
File is a splash image to be shown on top of a Trusted Web Activity while the web contents
are loading.
customtabs/src/android/support/customtabs/CustomTabsService.java