Validate hash_sha256 checksum on .crx update.

chrome/browser/extensions/extension_service.cc

 // Copyright (c) 2013 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/extension_service.h"
 
 #include <algorithm>
 #include <iterator>
 #include <set>
 
@@ skipping 458 matching lines @@
         state == extensions::BLACKLISTED_POTENTIALLY_UNWANTED ||
         state == extensions::BLACKLISTED_CWS_POLICY_VIOLATION)
       greylist_.Insert(*it);
   }
 }
 
 bool ExtensionService::UpdateExtension(const std::string& id,
                                        const base::FilePath& extension_path,
                                        bool file_ownership_passed,
                                        CrxInstaller** out_crx_installer) {
+  return ExtensionService::CheckAndUpdateExtension(
+      id, extension_path, std::string(), file_ownership_passed,
+      out_crx_installer);
+}
+
+bool ExtensionService::CheckAndUpdateExtension(
+    const std::string& id,
+    const base::FilePath& extension_path,
+    const std::string& package_hash,
+    bool file_ownership_passed,
+    CrxInstaller** out_crx_installer) {
   CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   if (browser_terminating_) {
     LOG(WARNING) << "Skipping UpdateExtension due to browser shutdown";
     // Leak the temp file at extension_path. We don't want to add to the disk
     // I/O burden at shutdown, we can't rely on the I/O completing anyway, and
     // the file is in the OS temp directory which should be cleaned up for us.
     return false;
   }
 
   const extensions::PendingExtensionInfo* pending_extension_info =
@@ skipping 59 matching lines @@
 
   if (extension) {
     installer->set_is_ephemeral(extension_prefs_->IsEphemeralApp(id));
     installer->set_do_not_sync(extension_prefs_->DoNotSync(id));
   }
 
   installer->set_creation_flags(creation_flags);
 
   installer->set_delete_source(file_ownership_passed);
   installer->set_install_cause(extension_misc::INSTALL_CAUSE_UPDATE);
-  installer->InstallCrx(extension_path);
+  installer->CheckAndInstallCrx(extension_path, package_hash);
 
   if (out_crx_installer)
     *out_crx_installer = installer.get();
 
   return true;
 }
 
 void ExtensionService::ReloadExtensionImpl(
     // "transient" because the process of reloading may cause the reference
     // to become invalid. Instead, use |extension_id|, a copy.
@@ skipping 1960 matching lines @@
 }
 
 void ExtensionService::OnProfileDestructionStarted() {
   ExtensionIdSet ids_to_unload = registry_->enabled_extensions().GetIDs();
   for (ExtensionIdSet::iterator it = ids_to_unload.begin();
        it != ids_to_unload.end();
        ++it) {
     UnloadExtension(*it, UnloadedExtensionInfo::REASON_PROFILE_SHUTDOWN);
   }
 }