Update from https://crrev.com/333737

base/android/apk_assets.h

+// Copyright 2015 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 BASE_ANDROID_APK_ASSETS_H_
+#define BASE_ANDROID_APK_ASSETS_H_
+
+#include <string>
+
+#include "base/android/jni_android.h"
+#include "base/files/memory_mapped_file.h"
+#include "base/posix/global_descriptors.h"
+
+namespace base {
+namespace android {
+
+bool RegisterApkAssets(JNIEnv* env);
+
+// Opens an asset (e.g. a .pak file) from the apk.
+// Can be used from renderer process.
+// Fails if the asset is not stored uncompressed within the .apk.
+// Returns: The File Descriptor of the asset, or -1 upon failure.
+// Input arguments:
+// - |file_path|: Path to file within .apk. e.g.: assets/foo.pak
+// Output arguments:
+// - |region|: size & offset (in bytes) within the .apk of the asset.
+BASE_EXPORT int OpenApkAsset(
+    const std::string& file_path,
+    base::MemoryMappedFile::Region* region);
+
+// Registers an uncompressed asset from within the apk with GlobalDescriptors.
+// Returns: true in case of success, false otherwise.
+BASE_EXPORT bool RegisterApkAssetWithGlobalDescriptors(
+    base::GlobalDescriptors::Key key,
+    const std::string& file_path);
+
+}  // namespace android
+}  // namespace base
+
+#endif  // BASE_ANDROID_APK_ASSETS_H_