Add AwAssets into android_webview/native/public

android_webview/native/aw_assets.h

-// Copyright 2014 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.
-
-#ifndef ANDROID_WEBVIEW_NATIVE_AW_ASSETS_H_
-#define ANDROID_WEBVIEW_NATIVE_AW_ASSETS_H_
-
-#include <string>
-
-#include "base/android/jni_android.h"
-#include "base/posix/global_descriptors.h"
-
-namespace android_webview {
-namespace AwAssets {
-
-// Called by native to retrieve an asset (e.g. a .pak file) from the apk.
-// Returns: true in case of success, false otherwise.
-// Output arguments:
-// - |fd|: file descriptor to the apk. The caller takes the ownership.
-// - |offset|: offset in bytes from the start of the file
-// - |size|: size in bytes of the asset / resource.
-bool OpenAsset(const std::string& filename,
-               int* fd,
-               int64* offset,
-               int64* size);
-
-bool RegisterAssetWithGlobalDescriptors(base::GlobalDescriptors::Key key,
-                                        const std::string& asset_filename);
-
-}  // namespace AwAssets
-
-bool RegisterAwAssets(JNIEnv* env);
-
-}  // namsespace android_webview
-
-#endif  // ANDROID_WEBVIEW_NATIVE_AW_ASSETS_H_