Adding app_shim executable on Windows.

This is a small binary that runs Chrome with the given command-line
arguments. It is intended for use with Chrome apps, so that file types
can be associated with the shim, having a custom name (and in some
cases, icon) rather than simply the name of the Chrome binary.

BUG=130455

Review URL: https://codereview.chromium.org/179223003

Cr-Commit-Position: refs/heads/master@{#302749}

chrome/app_shim/DEPS

 include_rules = [
   "+chrome/grit/generated_resources.h",
+  "+chrome/installer/launcher_support",
 ]

chrome/app_shim/app_shim_win.gypi

+# 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.
+
+{
+  'targets': [
+    # This is the app shim on Windows. It is a small binary that simply runs
+    # Chrome, passing along any command-line arguments.
+    {
+      'target_name': 'app_shim',
+      'type': 'executable',
+      'dependencies': [
+        'launcher_support',
+        '../base/base.gyp:base',
+      ],
+      'sources': [
+        'win/app_shim.rc',
+        'win/app_shim_main.cc',
+      ],
+      'msvs_settings': {
+        'VCLinkerTool': {
+          'SubSystem': '2',     # Set /SUBSYSTEM:WINDOWS
+        },
+        'VCManifestTool': {
+          'AdditionalManifestFiles': [
+            'app_shim/win/app_shim.exe.manifest',
+          ],
+        },
+      },
+    },
+  ],  # targets
+}

chrome/app_shim/win/app_shim.exe.manifest

+<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
+<assembly xmlns="urn:schemas-microsoft-com:asm.v1" manifestVersion="1.0">
+
+  <!--The compatibility section will be merged from build/win/compatibility.manifest -->
+
+  <trustInfo xmlns="urn:schemas-microsoft-com:asm.v3">
+    <security>
+      <requestedPrivileges>
+        <requestedExecutionLevel level="asInvoker" />
+      </requestedPrivileges>
+    </security>
+  </trustInfo>
+
+</assembly>

chrome/app_shim/win/app_shim.rc

+IDR_MAINFRAME ICON "..\\..\\chrome\\app\\theme\\chromium\\win\\webstore.ico"

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;
+}

chrome/chrome.gyp

@@ -511,6 +511,7 @@
         },
       ],  # 'targets'
       'includes': [
+        'app_shim/app_shim_win.gypi',
         'chrome_process_finder.gypi',
         'metro_utils.gypi',
       ],