Introduce chrome.shell.createWindow stub API for app_shell

chrome/renderer/extensions/chrome_extensions_renderer_client.cc

Index: chrome/renderer/extensions/chrome_extensions_renderer_client.cc
diff --git a/chrome/renderer/extensions/chrome_extensions_renderer_client.cc b/chrome/renderer/extensions/chrome_extensions_renderer_client.cc
index c3ef38d762e82958ed71e89f9a7729acdb4d5c5f..cd0b732c0f422442dd9f67ee2e6c2bb8dc74483c 100644
--- a/chrome/renderer/extensions/chrome_extensions_renderer_client.cc
+++ b/chrome/renderer/extensions/chrome_extensions_renderer_client.cc
@@ -26,3 +26,12 @@ bool ChromeExtensionsRendererClient::IsIncognitoProcess() const {
 int ChromeExtensionsRendererClient::GetLowestIsolatedWorldId() const {
   return chrome::ISOLATED_WORLD_ID_EXTENSIONS;
 }
+
+void ChromeExtensionsRendererClient::RegisterNativeHandlers(
+    extensions::ModuleSystem* module_system,
+    extensions::ScriptContext* context) {
+}
+
+void ChromeExtensionsRendererClient::PopulateSourceMap(
+    ResourceBundleSourceMap* source_map) {
+}