Enforce the 'requirements' field in manifests.

chrome/browser/extensions/installed_loader.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/installed_loader.h"
 
 #include "base/file_path.h"
 #include "base/metrics/histogram.h"
 #include "base/stringprintf.h"
 #include "base/utf_string_conversions.h"
@@ skipping 58 matching lines @@
 void InstalledLoader::Load(const ExtensionInfo& info, bool write_to_prefs) {
   std::string error;
   scoped_refptr<const Extension> extension(NULL);
   if (info.extension_manifest.get()) {
     extension = Extension::Create(
         info.extension_path,
         info.extension_location,
         *info.extension_manifest,
         GetCreationFlags(&info),
         &error);
+    if (extension_prefs_->HasUnsupportedRequirements(extension->id())) {
+      std::vector<std::string> requirement_errors =
+          extension_prefs_->GetUnsupportedRequirements(extension->id());
+      extensions::Extension::InstallWarningVector install_warnings;
+      std::vector<std::string>::iterator it;
+      for (it = requirement_errors.begin(); it != requirement_errors.end();
+           ++it) {
+        install_warnings.push_back(Extension::InstallWarning(
+            Extension::InstallWarning::FORMAT_TEXT, *it));
+      }
+      const_cast<Extension*>(extension.get())->AddInstallWarnings(
+          install_warnings);
+    }
   } else {
     error = errors::kManifestUnreadable;
   }
 
   // Once installed, non-unpacked extensions cannot change their IDs (e.g., by
   // updating the 'key' field in their manifest).
   // TODO(jstritar): migrate preferences when unpacked extensions change IDs.
   if (extension &&
       extension->location() != Extension::LOAD &&
       info.extension_id != extension->id()) {
@@ skipping 213 matching lines @@
   if (extension_prefs_->AllowFileAccess(info->extension_id))
     flags |= Extension::ALLOW_FILE_ACCESS;
   if (extension_prefs_->IsFromWebStore(info->extension_id))
     flags |= Extension::FROM_WEBSTORE;
   if (extension_prefs_->IsFromBookmark(info->extension_id))
     flags |= Extension::FROM_BOOKMARK;
   return flags;
 }
 
 }  // namespace extensions