Adding the VerifyModule function (and helpers) to safe browsing.

chrome/browser/safe_browsing/module_integrity_verifier.h

+// 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.
+
+#ifndef CHROME_BROWSER_SAFE_BROWSING_MODULE_INTEGRITY_VERIFIER_H_
+#define CHROME_BROWSER_SAFE_BROWSING_MODULE_INTEGRITY_VERIFIER_H_
+
+#include <windows.h>
+#include <psapi.h>
+
+#include "base/files/file_path.h"
+#include "base/files/memory_mapped_file.h"
+#include "base/scoped_native_library.h"
+#include "base/win/pe_image.h"
+
+namespace safe_browsing {
+
+// This enum defines the possible module states VerifyModule can return.
+enum ModuleState {
+  MODULE_STATE_UNKNOWN,
+  MODULE_STATE_UNMODIFIED,
+  MODULE_STATE_MODIFIED,
+};
+
+// Helper to grab the addresses and size of the code section of a PEImage.
+// Returns two addresses: one for the dll loaded as a library, the other for the
+// dll loaded as data.
+bool GetCodeAddrsAndSize(const base::win::PEImage& mem_peimage,
+                         const base::win::PEImageAsData& disk_peimage,
+                         BYTE** mem_code_addr,
+                         BYTE** disk_code_addr,
+                         SIZE_T* code_size);
+
+// Helper to count the number of bytes differing between two pointers.
+int CountBytesDiffInPtr(intptr_t num_a, intptr_t num_b);
+
+// Examines the code section of the given module in memory and on disk, looking
+// for unexpected differences.
+ModuleState VerifyModule(const wchar_t* module_name);
+
+}  // namespace safe_browsing
+
+#endif  // CHROME_BROWSER_SAFE_BROWSING_MODULE_INTEGRITY_VERIFIER_H_