Add a commandline flag to chrome to validate crx files

chrome/browser/ui/startup/startup_browser_creator.cc

Index: chrome/browser/ui/startup/startup_browser_creator.cc
diff --git a/chrome/browser/ui/startup/startup_browser_creator.cc b/chrome/browser/ui/startup/startup_browser_creator.cc
index 250048b6d00e2b12e26647f2a52ff7c11587b0fc..fd2e6ede86a796542d099b167ff029f075a302ed 100644
--- a/chrome/browser/ui/startup/startup_browser_creator.cc
+++ b/chrome/browser/ui/startup/startup_browser_creator.cc
@@ -542,6 +542,18 @@ bool StartupBrowserCreator::ProcessCmdLineImpl(
     return false;
   }
 
+  if (command_line.HasSwitch(switches::kValidateCrx)) {
+    if (!process_startup) {
+      LOG(ERROR) << "chrome is already running; you must close all running "
+                 << "instances before running with the --"
+                 << switches::kValidateCrx << " flag";
+      return false;
+    }
+    extensions::StartupHelper helper;
+    helper.ValidateCrx(command_line);
+    return false;
+  }
+
   if (command_line.HasSwitch(switches::kLimitedInstallFromWebstore)) {
     extensions::StartupHelper helper;
     helper.LimitedInstallFromWebstore(command_line, last_used_profile,