Upstream most of the iOS WebUI support in ios/web/

ios/web/webui/web_ui_ios_controller_factory_registry.cc

+// Copyright 2014 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 "ios/web/webui/web_ui_ios_controller_factory_registry.h"
+
+#include "base/lazy_instance.h"
+#include "url/gurl.h"
+#include "url/url_constants.h"
+
+namespace web {
+
+base::LazyInstance<std::vector<WebUIIOSControllerFactory*> > g_factories =

[Eugene But (OOO till 7-30), 2015/04/28 20:23:01]

NIT: no need for space between '>'

+    LAZY_INSTANCE_INITIALIZER;
+
+void WebUIIOSControllerFactory::RegisterFactory(
+    WebUIIOSControllerFactory* factory) {
+  g_factories.Pointer()->push_back(factory);
+}
+
+WebUIIOSControllerFactoryRegistry*
+WebUIIOSControllerFactoryRegistry::GetInstance() {
+  return Singleton<WebUIIOSControllerFactoryRegistry>::get();
+}
+
+WebUIIOSController*
+WebUIIOSControllerFactoryRegistry::CreateWebUIIOSControllerForURL(
+    WebUIIOS* web_ui,
+    const GURL& url) const {
+  std::vector<WebUIIOSControllerFactory*>* factories = g_factories.Pointer();
+  for (size_t i = 0; i < factories->size(); ++i) {
+    WebUIIOSController* controller =
+        (*factories)[i]->CreateWebUIIOSControllerForURL(web_ui, url);
+    if (controller)
+      return controller;
+  }
+  return NULL;
+}
+
+WebUIIOSControllerFactoryRegistry::WebUIIOSControllerFactoryRegistry() {
+}
+
+WebUIIOSControllerFactoryRegistry::~WebUIIOSControllerFactoryRegistry() {
+}
+
+}  // namespace web