Asynchronously pre-fault the native library pages.

base/android/linker/linker_jni.cc

Index: base/android/linker/linker_jni.cc
diff --git a/base/android/linker/linker_jni.cc b/base/android/linker/linker_jni.cc
index 1a11639dd5364d3039591bd66da7201126d6d9bf..6e8369292bf17e475014a3269b2d6a32253ff71a 100644
--- a/base/android/linker/linker_jni.cc
+++ b/base/android/linker/linker_jni.cc
@@ -609,6 +609,44 @@ jstring GetLibraryFilePathInZipFile(JNIEnv* env,
   return env->NewStringUTF(buffer);
 }
 
+// Prefault the pages of a native library stored in a zip file.
+//
+// |env| is the current JNI environment handle.
+// |clazz| is the static class handle which is not used here.
+// |lib_name| is the library base name.
+// Returns true for success.
+jboolean PrefaultLibraryInZipFile(JNIEnv* env, jclass clazz,
+                                  jstring zip_filename, jstring lib_name) {
+  char path_in_zip[kMaxFilePathLengthInZip + 1];
+  crazy_status_t status;
+  String lib_name_str(env, lib_name);
+  String zip_filename_str(env, zip_filename);
+  int offset, size;
+
+  status = crazy_library_file_path_in_zip_file(lib_name_str.c_str(),
+                                               path_in_zip, 256);
+  if (status == CRAZY_STATUS_FAILURE) return false;
+  status = crazy_library_offset_size_in_zip_file(zip_filename_str.c_str(),
+                                                 path_in_zip, &offset, &size);
+  if (status == CRAZY_STATUS_FAILURE) return false;
+  status = crazy_prefault_library(zip_filename_str.c_str(), offset, size);
+  return true;
+}
+
+// Prefault the pages of a native library.
+//
+// |env| is the current JNI environment handle.
+// |clazz| is the static class handle which is not used here.
+// |lib_filename| is the library file name.
+// Returns true for success.
+jboolean PrefaultLibraryInFile(JNIEnv* env, jclass clazz,
+                               jstring lib_filename) {
+  String lib_filename_str(env, lib_filename);
+
+  return (crazy_prefault_library(lib_filename_str.c_str(), 0, -1)
+          == CRAZY_STATUS_SUCCESS);
+}
+
 // Check whether the device supports mapping the APK file with executable
 // permission.
 //
@@ -730,6 +768,21 @@ const JNINativeMethod kNativeMethods[] = {
      ")"
      "Ljava/lang/String;",
      reinterpret_cast<void*>(&GetLibraryFilePathInZipFile)},
+    {"nativePrefaultLibraryInFile",
+     "("
+     "Ljava/lang/String;"
+     ")"
+     "Z",
+     reinterpret_cast<void*>(&PrefaultLibraryInFile)
+    },
+    {"nativePrefaultLibraryInZipFile",
+     "("
+     "Ljava/lang/String;"
+     "Ljava/lang/String;"
+     ")"
+     "Z",
+     reinterpret_cast<void*>(&PrefaultLibraryInZipFile)
+    },
     {"nativeCheckMapExecSupport",
      "("
      "Ljava/lang/String;"