Revert of Revert of Add AwAssets into android_webview/native/public

android_webview/native/aw_assets.cc

-// 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.
-
-#include <jni.h>
-
-#include "android_webview/native/aw_assets.h"
-
-#include "base/android/jni_array.h"
-#include "base/android/jni_string.h"
-#include "base/android/scoped_java_ref.h"
-#include "jni/AwAssets_jni.h"
-
-namespace android_webview {
-namespace AwAssets {
-
-bool OpenAsset(const std::string& filename,
-               int* fd,
-               int64* offset,
-               int64* size) {
-  JNIEnv* env = base::android::AttachCurrentThread();
-  ScopedJavaLocalRef<jlongArray> jarr = Java_AwAssets_openAsset(
-      env,
-      base::android::GetApplicationContext(),
-      base::android::ConvertUTF8ToJavaString(env, filename).Release());
-  std::vector<jlong> results;
-  base::android::JavaLongArrayToLongVector(env, jarr.obj(), &results);
-  DCHECK_EQ(3U, results.size());
-  *fd = static_cast<int>(results[0]);
-  *offset = results[1];
-  *size = results[2];
-  return *fd != -1;
-}
-
-bool RegisterAssetWithGlobalDescriptors(base::GlobalDescriptors::Key key,
-                                        const std::string& asset_filename) {
-  int asset_fd = 0;
-  int64 asset_off = 0;
-  int64 asset_len = 0;
-  bool result =
-      AwAssets::OpenAsset(asset_filename, &asset_fd, &asset_off, &asset_len);
-  if (result) {
-    base::GlobalDescriptors::GetInstance()->Set(
-        key, asset_fd, base::MemoryMappedFile::Region(asset_off, asset_len));
-  }
-  return result;
-}
-
-}  // namespace AwAssets
-
-bool RegisterAwAssets(JNIEnv* env) {
-  return RegisterNativesImpl(env);
-}
-
-}  // namespace android_webview