Merge "More robust DRM support, including tests."

    method public android.drm.DrmConvertedStatus closeConvertSession(int);

    method public android.drm.DrmConvertedStatus convertData(int, byte[]);

    method public String[] getAvailableDrmEngines();

    method @NonNull public java.util.Collection<android.drm.DrmSupportInfo> getAvailableDrmSupportInfo();

    method public android.content.ContentValues getConstraints(String, int);

    method public android.content.ContentValues getConstraints(android.net.Uri, int);

    method public int getDrmObjectType(String, String);

package android.drm;

import android.annotation.NonNull;

import android.content.ContentResolver;

import android.content.ContentValues;

import android.content.Context;

import java.io.IOException;

import java.lang.ref.WeakReference;

import java.util.ArrayList;

import java.util.Arrays;

import java.util.Collection;

import java.util.HashMap;

import java.util.concurrent.atomic.AtomicBoolean;

        return descriptions.toArray(drmEngines);

    }

    /**

     * Retrieves information about all the DRM plug-ins (agents) that are

     * registered with the DRM framework.

     *

     * @return List of all the DRM plug-ins (agents) that are registered with

     *         the DRM framework.

     */

    public @NonNull Collection<DrmSupportInfo> getAvailableDrmSupportInfo() {

        return Arrays.asList(_getAllSupportInfo(mUniqueId));

    }

    /**

     * Retrieves constraint information for rights-protected content.

     *