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

ios/web/public/web_ui_ios_data_source.h

Index: ios/web/public/web_ui_ios_data_source.h
diff --git a/ios/web/public/web_ui_ios_data_source.h b/ios/web/public/web_ui_ios_data_source.h
new file mode 100644
index 0000000000000000000000000000000000000000..b714579956d3134f11c69bc8c6109554e7419bb8
--- /dev/null
+++ b/ios/web/public/web_ui_ios_data_source.h
@@ -0,0 +1,60 @@
+// 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.
+
+#ifndef IOS_WEB_PUBLIC_WEB_UI_IOS_DATA_SOURCE_H_
+#define IOS_WEB_PUBLIC_WEB_UI_IOS_DATA_SOURCE_H_
+
+#include "base/callback.h"
+#include "base/strings/string16.h"
+#include "base/supports_user_data.h"
+
+namespace base {
+class DictionaryValue;
+class RefCountedMemory;
+}
+
+namespace web {
+class BrowserState;
+
+// A data source that can help with implementing the common operations needed by
+// WebUIIOS pages.
+class WebUIIOSDataSource : public base::SupportsUserData {
+ public:
+  ~WebUIIOSDataSource() override {}
+

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

ditto

+  static WebUIIOSDataSource* Create(const std::string& source_name);
+
+  // Adds a WebUIIOS data source to |browser_state|.
+  static void Add(BrowserState* browser_state, WebUIIOSDataSource* source);
+
+  // Adds a string keyed to its name to our dictionary.
+  virtual void AddString(const std::string& name,
+                         const base::string16& value) = 0;
+
+  // Adds a string keyed to its name to our dictionary.
+  virtual void AddString(const std::string& name, const std::string& value) = 0;
+
+  // Adds a localized string with resource |ids| keyed to its name to our
+  // dictionary.
+  virtual void AddLocalizedString(const std::string& name, int ids) = 0;
+
+  // Adds a boolean keyed to its name to our dictionary.
+  virtual void AddBoolean(const std::string& name, bool value) = 0;
+
+  // Sets the path which will return the JSON strings.
+  virtual void SetJsonPath(const std::string& path) = 0;
+
+  // Adds a mapping between a path name and a resource to return.
+  virtual void AddResourcePath(const std::string& path, int resource_id) = 0;
+
+  // Sets the resource to returned when no other paths match.
+  virtual void SetDefaultResource(int resource_id) = 0;
+
+  // The following map to methods on URLDataSource. See the documentation there.
+  virtual void DisableDenyXFrameOptions() = 0;
+};
+
+}  // namespace web
+
+#endif  // IOS_WEB_PUBLIC_WEB_UI_IOS_DATA_SOURCE_H_