Enforce the 'requirements' field in manifests.

chrome/browser/ui/webui/extensions/extension_settings_handler.cc

Index: chrome/browser/ui/webui/extensions/extension_settings_handler.cc
diff --git a/chrome/browser/ui/webui/extensions/extension_settings_handler.cc b/chrome/browser/ui/webui/extensions/extension_settings_handler.cc
index 6bbd86f635e54858d1ad958d5c744e65aed8d016..7b4b552e1d6e0441cfa4d75d671d0288afbaf00e 100644
--- a/chrome/browser/ui/webui/extensions/extension_settings_handler.cc
+++ b/chrome/browser/ui/webui/extensions/extension_settings_handler.cc
@@ -18,6 +18,7 @@
 #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"
@@ -620,6 +621,11 @@ void ExtensionSettingsHandler::HandleEnableMessage(const ListValue* args) {
           web_ui()->GetWebContents());
       extensions::ShowExtensionDisabledDialog(
           extension_service_, browser, extension);
+    } else if (prefs->HasUnsupportedRequirements(extension_id)) {
+      // TODO(eriq): i18n
+      ExtensionErrorReporter::GetInstance()->ReportError(
+          ASCIIToUTF16("Cannot enable, not all requirements are met."),
+          true /* be noisy */);
     } else {
       extension_service_->EnableExtension(extension_id);
     }