Enforce the 'requirements' field in manifests.

chrome/browser/ui/webui/extensions/extension_settings_handler.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/ui/webui/extensions/extension_settings_handler.h"
 
 #include "base/auto_reset.h"
 #include "base/base64.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/file_util.h"
+#include "base/string_util.h"
 #include "base/string_number_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "base/version.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/debugger/devtools_window.h"
 #include "chrome/browser/extensions/crx_installer.h"
 #include "chrome/browser/extensions/extension_disabled_ui.h"
+#include "chrome/browser/extensions/extension_error_reporter.h"
 #include "chrome/browser/extensions/extension_host.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/extensions/extension_warning_set.h"
 #include "chrome/browser/extensions/lazy_background_task_queue.h"
 #include "chrome/browser/extensions/unpacked_installer.h"
 #include "chrome/browser/extensions/updater/extension_updater.h"
 #include "chrome/browser/google/google_util.h"
 #include "chrome/browser/managed_mode.h"
 #include "chrome/browser/prefs/pref_service.h"
@@ skipping 586 matching lines @@
     return;
   }
 
   if (enable_str == "true") {
     extensions::ExtensionPrefs* prefs = extension_service_->extension_prefs();
     if (prefs->DidExtensionEscalatePermissions(extension_id)) {
       Browser* browser = browser::FindBrowserWithWebContents(
           web_ui()->GetWebContents());
       extensions::ShowExtensionDisabledDialog(
           extension_service_, browser, extension);
+    } else if ((prefs->GetDisableReasons(extension_id) &
+                   Extension::DISABLE_UNSUPPORTED_REQUIREMENT) &&
+               !requirements_checker_.get()) {
+      // Recheck the requirements.
+      scoped_refptr<const Extension> extension =
+          extension_service_->GetExtensionById(extension_id,
+                                               true /* include disabled */);
+      requirements_checker_.reset(new extensions::RequirementsChecker());
+      requirements_checker_->Check(
+          extension,
+          base::Bind(&ExtensionSettingsHandler::OnRequirementsChecked,
+                     AsWeakPtr(), extension_id));
     } else {
       extension_service_->EnableExtension(extension_id);
     }
   } else {
     extension_service_->DisableExtension(
         extension_id, Extension::DISABLE_USER_ACTION);
   }
 }
 
 void ExtensionSettingsHandler::HandleEnableIncognitoMessage(
@@ skipping 243 matching lines @@
 #else
   return NULL;
 #endif  // !defined(OS_ANDROID)
 }
 
 void ExtensionSettingsHandler::InspectExtensionHost(
     extensions::ExtensionHost* host) {
   if (host)
     DevToolsWindow::OpenDevToolsWindow(host->render_view_host());
 }
+
+void ExtensionSettingsHandler::OnRequirementsChecked(
+    std::string extension_id,
+    std::vector<std::string> requirement_errors) {
+  if (requirement_errors.empty()) {
+    extension_service_->EnableExtension(extension_id);
+  } else {
+    ExtensionErrorReporter::GetInstance()->ReportError(
+        UTF8ToUTF16(JoinString(requirement_errors, ' ')),
+        true /* be noisy */);
+  }
+  requirements_checker_.reset();
+}