Photo Picker dialog: Convert to AIDL for easier security review.

chrome/android/java/src/org/chromium/chrome/browser/photo_picker/IDecoderService.aidl

+// 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.chrome.browser.photo_picker;
+
+import android.os.Bundle;
+
+import IDecoderServiceCallback;
+
+/**
+ * This interface is called by the Photo Picker to start image decoding jobs in
+ * a separate process.
+ */
+interface IDecoderService {
+  /**
+   * Decode an image.
+   * @param payload The data containing the details for the decoding request.
+   */
+  oneway void decodeImage(in Bundle payload, IDecoderServiceCallback listener);
+}