[ios] TabIdTabHelper

ios/chrome/browser/web/tab_id_tab_helper.h

Index: ios/chrome/browser/web/tab_id_tab_helper.h
diff --git a/ios/chrome/browser/web/tab_id_tab_helper.h b/ios/chrome/browser/web/tab_id_tab_helper.h
new file mode 100644
index 0000000000000000000000000000000000000000..b515522eefa78b2220ed4125a01b6133d96e7be5
--- /dev/null
+++ b/ios/chrome/browser/web/tab_id_tab_helper.h
@@ -0,0 +1,27 @@
+// Copyright 2017 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_CHROME_BROWSER_WEB_TAB_ID_TAB_HELPER_H_
+#define IOS_CHROME_BROWSER_WEB_TAB_ID_TAB_HELPER_H_
+
+#include "base/macros.h"
+#import "ios/web/public/web_state/web_state_user_data.h"
+
+// Handles creating a unique identifier, which is stable across cold starts.
+class TabIDTabHelper : public web::WebStateUserData<TabIDTabHelper> {

[Eugene But (OOO till 7-30), 2017/06/23 22:44:57]

s/TabIDTabHelper/TabIdTabHelper to follow C++ Style Guide?

https://engdoc.corp.google.com/eng/doc/devguide/cpp/styleguide.shtml?cl=head#...

Yes, Chromium code is very inconsistent with this :)

[sdefresne, 2017/06/26 10:28:55]

Well technically, Id is an abbreviation and should not be used either
(https://google.github.io/styleguide/cppguide.html#General_Naming_Rules), so
this should be TabIdentifierTabHelper.

I agree that TabIdTabHelper looks better than TabIDTabHelper.

[Eugene But (OOO till 7-30), 2017/06/26 14:09:44]

I think Style Guide is fine with ID abbreviation. It even has an example:

int cstmr_id;              // Deletes internal letters.

where |cstmr| is not fine, but |id| part is.

[edchin, 2017/06/26 16:20:57]

Done.

+ public:
+  ~TabIDTabHelper() override;
+
+  // Returns a unique identifier for this tab.
+  NSString* tab_id() const { return tab_id_; }
+
+ private:
+  explicit TabIDTabHelper(web::WebState* web_state);
+  friend class web::WebStateUserData<TabIDTabHelper>;

[sdefresne, 2017/06/26 10:28:55]

optional: move this before the declaration of the constructor (this is a class
declaration and the style recommend the following order in a section "types
(including typedef, using, and nested structs and classes), constants, factory
functions, constructors, assignment operators, destructor, all other methods,
data members".

So that would be:

 private:
  friend class web::WebStateUserData<TabIDTabHelper>;
  explicit TabIDTabHelper(web::WebState* web_state);
  __strong NSString* tab_id_;

[edchin, 2017/06/26 16:20:57]

Done.

+  __strong NSString* tab_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(TabIDTabHelper);
+};
+
+#endif  // IOS_CHROME_BROWSER_WEB_TAB_ID_TAB_HELPER_H_