When changing Ready Mode state from within an IE process, use chrome_launcher...

chrome_frame/update_launcher.cc

+// Copyright (c) 2011 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 "chrome_frame/update_launcher.h"
+
+#include <windows.h>
+#include <Shellapi.h>
+
+#include "google_update_idl.h"  // NOLINT
+
+namespace {
+
+const wchar_t kChromeFrameGuid[] = L"{8BA986DA-5100-405E-AA35-86F34A02ACBF}";
+
+const DWORD kLaunchFailureExitCode = 0xFF;
+
+const wchar_t kUpdateCommandFlag[] = L"--update-cmd";
+
+// Waits indefinitely for the provided process to exit. Returns the process's
+// exit code, or kLaunchFailureExitCode if an error occurs in the waiting.
+DWORD WaitForProcessExitCode(HANDLE handle) {
+  DWORD exit_code = 0;
+
+  DWORD wait_result = WaitForSingleObject(handle, INFINITE);
+
+  if (wait_result == WAIT_OBJECT_0 && ::GetExitCodeProcess(handle, &exit_code))
+    return exit_code;
+
+  return kLaunchFailureExitCode;
+}
+
+}  // namespace
+
+namespace update_launcher {
+
+std::wstring GetUpdateCommandFromArguments(const wchar_t* command_line) {
+  if (command_line == NULL)
+    return L"";
+
+  int num_args = 0;
+  wchar_t** args = NULL;
+  args = ::CommandLineToArgvW(command_line, &num_args);

[robertshield, 2011/01/24 15:08:42]

The caller is supposed to free args when done (there's another case in
chrome_launcher.cc where this isn't done).
http://msdn.microsoft.com/en-us/library/bb776391(v=vs.85).aspx

[erikwright (departed), 2011/01/24 17:17:14]

Done.

+
+  if (num_args != 3)
+    return L"";
+
+  if (_wcsicmp(args[1], kUpdateCommandFlag) != 0)

[robertshield, 2011/01/24 15:08:42]

You should also check that args isn't NULL, to be safe.

[erikwright (departed), 2011/01/24 17:17:14]

Done.

+    return L"";
+
+  return args[2];
+}
+
+// Because we do not have 'base' and all of its pretty RAII helpers, please
+// ensure that this function only ever contains a single 'return', in order
+// to reduce the chance of introducing a leak.
+DWORD LaunchUpdateCommand(const std::wstring& command) {
+  DWORD exit_code = kLaunchFailureExitCode;
+
+  HRESULT hr = ::CoInitialize(NULL);
+
+  if (SUCCEEDED(hr)) {
+    IProcessLauncher* ipl = NULL;
+    HANDLE process = NULL;
+
+    hr = ::CoCreateInstance(__uuidof(ProcessLauncherClass), NULL,
+                            CLSCTX_ALL, __uuidof(IProcessLauncher),
+                            reinterpret_cast<void**>(&ipl));
+
+    if (SUCCEEDED(hr)) {
+      ULONG_PTR phandle = NULL;
+      DWORD id = ::GetCurrentProcessId();
+
+      hr = ipl->LaunchCmdElevated(kChromeFrameGuid,
+                                  command.c_str(), id, &phandle);
+      if (SUCCEEDED(hr)) {
+        process = reinterpret_cast<HANDLE>(phandle);
+        exit_code =  WaitForProcessExitCode(process);

[robertshield, 2011/01/24 15:08:42]

nit: one too many spaces.

[erikwright (departed), 2011/01/24 17:17:14]

Done.

+      }
+    }
+
+    if (process)
+      ::CloseHandle(process);
+    if (ipl)
+      ipl->Release();
+
+    ::CoUninitialize();
+  }
+
+  return exit_code;
+}
+
+}  // namespace process_launcher