plugins: move NativeLibrary into base.

base/native_library_win.cc

+// Copyright (c) 2009 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/native_library.h"
+
+#include <windows.h>
+
+#include "base/file_path.h"
+#include "base/path_service.h"
+
+namespace base {
+
+// static
+NativeLibrary LoadNativeLibrary(const FilePath& library_path) {
+  // Switch the current directory to the library directory as the library
+  // may have dependencies on DLLs in this directory.
+  bool restore_directory = false;
+  std::wstring current_directory;
+  if (PathService::Get(base::DIR_CURRENT, &current_directory)) {
+    FilePath plugin_path = library_path.DirName();
+    if (!plugin_path.value().empty()) {
+      PathService::SetCurrentDirectory(plugin_path.value());
+      restore_directory = true;
+    }
+  }
+
+  HMODULE module = LoadLibrary(library_path.value().c_str());
+  if (restore_directory)
+    PathService::SetCurrentDirectory(current_directory);
+
+  return module;
+}
+
+// static
+void UnloadNativeLibrary(NativeLibrary library) {
+  FreeLibrary(library);
+}
+
+// static
+void* GetFunctionPointerFromNativeLibrary(NativeLibrary library,
+                                          NativeLibraryFunctionNameType name) {
+  return GetProcAddress(library, name);
+}
+
+}  // namespace base