[Clank] Add JNI interface for media persistent license storage

media/base/android/java/src/org/chromium/media/MediaDrmStorageBridge.java

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.media;
+
+import android.annotation.TargetApi;
+import android.os.Build;
+
+import org.chromium.base.Callback;
+import org.chromium.base.annotations.JNINamespace;
+import org.chromium.base.annotations.MainDex;
+
+/**
+ * Origin isolated media drm scope id storage. Isolated origin is guranteed by native
+ * implementation. Thus no origin information is stored here.
+ */
+@JNINamespace("media")
+@MainDex
+@TargetApi(Build.VERSION_CODES.M)
+class MediaDrmStorageBridge {
+    private static final long INVALID_NATIVE_MEDIA_DRM_STORAGE_BRIDGE = -1;
+
+    private long mNativeMediaDrmStorageBridge;
+
+    /**
+     * Information that need to be persistent on the device. Exposed to JNI.
+     */
+    @MainDex
+    static class PersistentInfo {
+        // EME session ID, which is generated randomly.
+        private final byte[] mEmeId;
+
+        // Key set ID used to identify persistent license in MediaDrm.
+        private final byte[] mKeySetId;
+
+        // Mime type for the license.
+        private final String mMimeType;
+
+        PersistentInfo(byte[] emeId, byte[] keySetId, String mime) {
+            mEmeId = emeId;
+            mKeySetId = keySetId;
+            mMimeType = mime;
+        }
+    }
+
+    MediaDrmStorageBridge(long nativeMediaDrmStorageBridge) {
+        mNativeMediaDrmStorageBridge = nativeMediaDrmStorageBridge;
+        assert isNativeMediaDrmStorageValid();
+    }
+
+    /**
+     * Called when device provisioning is finished.
+     */
+    void onProvisioned(Callback<Boolean> cb) {
+        if (isNativeMediaDrmStorageValid()) {
+            nativeOnProvisioned(mNativeMediaDrmStorageBridge, cb);
+        } else {
+            cb.onResult(true);
+        }
+    }
+
+    /**
+     * Load |emeId|'s storage into memory.
+     */
+    void loadInfo(byte[] emeId, Callback<PersistentInfo> cb) {
+        if (isNativeMediaDrmStorageValid()) {
+            nativeOnLoadInfo(mNativeMediaDrmStorageBridge, emeId, cb);
+        } else {
+            cb.onResult(null);
+        }
+    }
+
+    /**
+     * Save persistent information. Override the existing value.
+     */
+    void saveInfo(PersistentInfo info, Callback<Boolean> cb) {
+        if (isNativeMediaDrmStorageValid()) {
+            nativeOnSaveInfo(mNativeMediaDrmStorageBridge, info, cb);
+        } else {
+            cb.onResult(false);
+        }
+    }
+
+    /**
+     * Remove persistent information related |emeId|.
+     */
+    void clearInfo(byte[] emeId, Callback<Boolean> cb) {
+        if (isNativeMediaDrmStorageValid()) {
+            nativeOnClearInfo(mNativeMediaDrmStorageBridge, emeId, cb);
+        } else {
+            cb.onResult(true);
+        }
+    }
+
+    private boolean isNativeMediaDrmStorageValid() {
+        return mNativeMediaDrmStorageBridge != INVALID_NATIVE_MEDIA_DRM_STORAGE_BRIDGE;
+    }
+
+    private native void nativeOnProvisioned(long nativeMediaDrmStorageBridge, Callback<Boolean> cb);
+    private native void nativeOnLoadInfo(
+            long nativeMediaDrmStorageBridge, byte[] sessionId, Callback<PersistentInfo> cb);
+    private native void nativeOnSaveInfo(
+            long nativeMediaDrmStorageBridge, PersistentInfo info, Callback<Boolean> cb);
+    private native void nativeOnClearInfo(
+            long nativeMediaDrmStorageBridge, byte[] sessionId, Callback<Boolean> cb);
+}