Validate hash_sha256 checksum on .crx update.

chrome/browser/extensions/crx_installer.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 "chrome/browser/extensions/crx_installer.h"
 
 #include <map>
 #include <set>
 
 #include "base/bind.h"
@@ skipping 152 matching lines @@
 
 CrxInstaller::~CrxInstaller() {
   // Make sure the UI is deleted on the ui thread.
   if (client_) {
     BrowserThread::DeleteSoon(BrowserThread::UI, FROM_HERE, client_);
     client_ = NULL;
   }
 }
 
 void CrxInstaller::InstallCrx(const base::FilePath& source_file) {
+  CheckAndInstallCrx(source_file, std::string());
+}
+
+void CrxInstaller::CheckAndInstallCrx(const base::FilePath& source_file,
+                                      const std::string& package_hash) {
   ExtensionService* service = service_weak_.get();
   if (!service || service->browser_terminating())
     return;
 
   NotifyCrxInstallBegin();
 
   source_file_ = source_file;
 
-  scoped_refptr<SandboxedUnpacker> unpacker(
-      new SandboxedUnpacker(source_file,
-                            install_source_,
-                            creation_flags_,
-                            install_directory_,
-                            installer_task_runner_.get(),
-                            this));
+  scoped_refptr<SandboxedUnpacker> unpacker(new SandboxedUnpacker(
+      source_file, package_hash, install_source_, creation_flags_,
+      install_directory_, installer_task_runner_.get(), this));
 
   if (!installer_task_runner_->PostTask(
           FROM_HERE,
           base::Bind(&SandboxedUnpacker::Start, unpacker.get())))
     NOTREACHED();
 }
 
 void CrxInstaller::InstallUserScript(const base::FilePath& source_file,
                                      const GURL& download_url) {
   DCHECK(!download_url.is_empty());
@@ skipping 704 matching lines @@
   if (!prefs->DidExtensionEscalatePermissions(extension()->id()))
     return;
 
   if (client_) {
     AddRef();  // Balanced in InstallUIProceed() and InstallUIAbort().
     client_->ConfirmReEnable(this, extension());
   }
 }
 
 }  // namespace extensions