Adding app_shim executable on Windows.

chrome/app_shim/win/app_shim_main.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 <windows.h>
+
+#include <string>
+
+#include "base/command_line.h"
+#include "base/files/file_path.h"
+#include "base/logging.h"
+#include "base/process/launch.h"
+#include "chrome/installer/launcher_support/chrome_launcher_support.h"
+
+namespace {
+
+// Return codes.
+const int kOK = 0;
+const int kNoProgram = 1;
+const int kLaunchFailure = 2;
+
+// Command-line switches.
+const char kChromeSxS[] = "chrome-sxs";
+
+base::FilePath GetChromeExePath(bool is_canary) {
+  return is_canary ? chrome_launcher_support::GetAnyChromeSxSPath()
+                   : chrome_launcher_support::GetAnyChromePath();
+}
+
+}  // namespace
+
+// This program runs chrome.exe, passing its arguments on to the Chrome binary.
+// It uses the Windows registry to find chrome.exe (and hence it only works if
+// Chrome/Chromium has been properly installed). It terminates as soon as the
+// program is launched. It is intended to allow file types to be associated with
+// Chrome apps, with a custom name (and in some cases, icon) rather than simply
+// the name of the Chrome binary.
+//
+// Usage: app_shim_win [--chrome-sxs] -- [CHROME_ARGS...]
+//
+// The -- is required if switches are to be passed to Chrome; any switches
+// before the -- will be interpreted by app_shim_win, and not passed to Chrome.
+//
+// If --chrome-sxs is specified, looks for the SxS (Canary) build of Chrome.
+// This will always fail for Chromium.
+int WINAPI wWinMain(HINSTANCE instance,
+                    HINSTANCE prev_instance,
+                    wchar_t* /*command_line*/,
+                    int show_command) {
+  CommandLine::Init(0, nullptr);
+
+  // Log to stderr. Otherwise it will log to a file by default.
+  logging::LoggingSettings logging_settings;
+  logging_settings.logging_dest = logging::LOG_TO_SYSTEM_DEBUG_LOG;
+  logging::InitLogging(logging_settings);
+
+  // Get the command-line for the Chrome binary.
+  // --chrome-sxs on the command line means we should run the canary binary.
+  bool is_canary =
+      base::CommandLine::ForCurrentProcess()->HasSwitch(kChromeSxS);
+  base::FilePath chrome_path = GetChromeExePath(is_canary);
+  if (chrome_path.empty()) {
+    LOG(ERROR) << "Could not find chrome.exe path in the registry.";
+    return kNoProgram;
+  }
+  CommandLine command_line(chrome_path);
+
+  // Get the command-line arguments for the subprocess, consisting of the
+  // arguments (but not switches) to this binary. This gets everything after the
+  // "--".
+  for (const auto& arg : CommandLine::ForCurrentProcess()->GetArgs())
+    command_line.AppendArgNative(arg);
+
+  if (!base::LaunchProcess(command_line, base::LaunchOptions(), nullptr)) {
+    LOG(ERROR) << "Could not run chrome.exe.";
+    return kLaunchFailure;
+  }
+
+  return kOK;
+}