Implementing app command to query EULA acceptance state for Chrome.

chrome/browser/extensions/app_host/app_host_main.cc

 // Copyright (c) 2012 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 "base/at_exit.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/logging.h"
 #include "base/process_util.h"
 #include "chrome/browser/extensions/app_host/binaries_installer.h"
 #include "chrome/browser/extensions/app_host/update.h"
 #include "chrome/installer/launcher_support/chrome_launcher_support.h"
 
+namespace {
+
+HRESULT LaunchChromeAndProceed(const CommandLine& cmd_line) {
+  bool success = base::LaunchProcess(cmd_line, base::LaunchOptions(), NULL);
+  if (success) {
+    LOG(INFO) << "Delegated to Chrome executable at "
+              << cmd_line.GetProgram().value();
+  } else {
+    LOG(INFO) << "Failed to launch Chrome executable at "
+              << cmd_line.GetProgram().value();
+  }
+  return success ? S_OK : E_FAIL;
+}
+
+HRESULT LaunchChromeAndWait(const CommandLine& cmd_line) {
+  const DWORD kTimeOutInMilliseconds = 20000;
+  HANDLE proc = 0;
+  bool success = base::LaunchProcess(cmd_line, base::LaunchOptions(), &proc);
+  if (!success) {
+    LOG(INFO) << "Failed to launch Chrome executable at "
+              << cmd_line.GetProgram().value();
+    return E_FAIL;
+  }
+
+  LOG(INFO) << "Delegated to Chrome executable at "
+            << cmd_line.GetProgram().value();
+  DWORD res = WaitForSingleObject(proc, kTimeOutInMilliseconds);
+  if (res != WAIT_OBJECT_0) {
+    LOG(INFO) << "  Failed to wailt.";
+    return E_FAIL;
+  }
+
+  if (!GetExitCodeProcess(proc, &res)) {
+    LOG(INFO) << "  Failed to get exit code.";
+    return E_FAIL;
+  }
+  // Since we know that the process has terminated, we need not worry about
+  // the case where |res| should be interested as STILL_ACTIVE.
+
+  LOG(INFO) << "  Exit code: " << res;
+  DCHECK(res != STILL_ACTIVE);
+  return res;
+}
+
+}  // namespace
+
 int APIENTRY wWinMain(HINSTANCE, HINSTANCE, wchar_t*, int) {
   base::AtExitManager exit_manager;
 
+  // From chrome_switches.cc
+  const char kQueryEULAAcceptance[] = "query-eula-acceptance";
+
   // Initialize the commandline singleton from the environment.
   CommandLine::Init(0, NULL);
 
   FilePath chrome_exe(chrome_launcher_support::GetAnyChromePath());
   if (chrome_exe.empty()) {
     LOG(INFO) << "No Chrome executable could be found. Let's install it.";
     HRESULT hr = app_host::InstallBinaries();
     if (FAILED(hr)) {
       LOG(ERROR) << "Failed to install the Chrome Binaries. Error: " << hr;
-      return 1;
+      return E_FAIL;
     } else {
       chrome_exe = chrome_launcher_support::GetAnyChromePath();
       if (chrome_exe.empty()) {
         LOG(ERROR) << "Failed to find the Chrome Binaries despite a "
                    << "'successful' installation.";
-        return 1;
+        return E_FAIL;
       }
     }
   }
 
+  CommandLine command_line(*CommandLine::ForCurrentProcess());
   CommandLine chrome_exe_command_line(chrome_exe);
-  chrome_exe_command_line.AppendArguments(
-      *CommandLine::ForCurrentProcess(), false);
-  // Launch Chrome before checking for update, for faster user experience.
-  bool launch_result = base::LaunchProcess(chrome_exe_command_line,
-                                           base::LaunchOptions(), NULL);
-  if (launch_result)
-    LOG(INFO) << "Delegated to Chrome executable at " << chrome_exe.value();
-  else
-    LOG(INFO) << "Failed to launch Chrome executable at " << chrome_exe.value();
+  chrome_exe_command_line.AppendArguments(command_line, false);
 
-  app_host::EnsureAppHostUpToDate();
+  bool wait_for_chrome = false;
+  if (command_line.HasSwitch(kQueryEULAAcceptance))
+    wait_for_chrome = true;
 
-  return !launch_result;
+  if (!wait_for_chrome) {
+    // Launch Chrome before checking for update, for faster user experience.
+    HRESULT ret = LaunchChromeAndProceed(chrome_exe_command_line);
+    app_host::EnsureAppHostUpToDate();
+    return ret;
+
+  } else {
+    // We wait, so do not slow things more by trying to update app_host.exe.
+    return LaunchChromeAndWait(chrome_exe_command_line);
+  }
 }