Update from https://crrev.com/328418

base/android/library_loader/library_loader_hooks.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 "base/android/library_loader/library_loader_hooks.h"
 
 #include "base/android/command_line_android.h"
 #include "base/android/jni_string.h"
 #include "base/android/library_loader/library_load_from_apk_status_codes.h"
+#include "base/android/library_loader/library_prefetcher.h"
 #include "base/at_exit.h"
 #include "base/metrics/histogram.h"
 #include "jni/LibraryLoader_jni.h"
 
 namespace base {
 namespace android {
 
 namespace {
 
 base::AtExitManager* g_at_exit_manager = NULL;
@@ skipping 95 matching lines @@
   return g_registration_callback(env, NULL);
 }
 
 void LibraryLoaderExitHook() {
   if (g_at_exit_manager) {
     delete g_at_exit_manager;
     g_at_exit_manager = NULL;
   }
 }
 
+static jboolean ForkAndPrefetchNativeLibrary(JNIEnv* env, jclass clazz) {
+  return NativeLibraryPrefetcher::ForkAndPrefetchNativeLibrary();
+}
+
 bool RegisterLibraryLoaderEntryHook(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 void SetVersionNumber(const char* version_number) {
   g_library_version_number = strdup(version_number);
 }
 
 jstring GetVersionNumber(JNIEnv* env, jobject jcaller) {
   return ConvertUTF8ToJavaString(env, g_library_version_number).Release();
 }
 
 LibraryProcessType GetLibraryProcessType(JNIEnv* env) {
   return static_cast<LibraryProcessType>(
       Java_LibraryLoader_getLibraryProcessType(env));
 }
 
 void InitAtExitManager() {
   g_at_exit_manager = new base::AtExitManager();
 }
 
 }  // namespace android
 }  // namespace base