private static PendingIntent createSessionId(Context context, int sessionId) {
        // Create a {@link PendingIntent} with empty Action to prevent using it other than
        // a session identifier.
        return PendingIntent.getActivity(context, sessionId, new Intent(), 0);
    }
Warm up the browser process.

Allows the browser application to pre-initialize itself in the background. Significantly
speeds up URL opening in the browser. This is asynchronous and can be called several times.

@param flags Reserved for future use.
@return      Whether the warmup was successful.
customtabs/src/android/support/customtabs/CustomTabsClient.java