Implement the 2016Q2 Translate UI designe spec out in

chrome/browser/ui/translate/translate_bubble_view_state_transition.h

 // Copyright 2013 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 CHROME_BROWSER_UI_TRANSLATE_TRANSLATE_BUBBLE_VIEW_STATE_TRANSITION_H_
 #define CHROME_BROWSER_UI_TRANSLATE_TRANSLATE_BUBBLE_VIEW_STATE_TRANSITION_H_
 
 #include "base/macros.h"
 #include "chrome/browser/ui/translate/translate_bubble_model.h"
 
+namespace translate {

[msw, 2016/04/29 20:00:00]

nit: add a blank line between the namespace and the enum (ditto on close)

[ftang, 2016/04/29 22:37:00]

Done.

+enum TranslateBubbleUiEvent {
+  // Bubble enters the options state.

[msw, 2016/04/29 20:00:00]

Give a more descriptive comment, maybe "The bubble started showing advanced
options."; ditto below.

[ftang, 2016/04/29 22:37:00]

Done.

+  SET_STATE_OPTIONS = 1,

[msw, 2016/04/29 20:00:00]

Why do you give explicit values to the enums? Remove those.
(if needed for consistency with old values, you can just leave the '= 1' for the
first entry and remove the rest...)

+
+  // Bubble leaves the options state.
+  LEAVE_STATE_OPTIONS = 2,
+
+  // User click the advanced link

[msw, 2016/04/29 20:00:00]

Add trailing periods on this comment and others below.

[msw, 2016/04/29 20:00:00]

It'd be nice if you used the same subject and tense in the comments throughout
("Bubble enters" vs. "User click")... I'd suggest "The user clicked", etc.

[ftang, 2016/04/29 22:37:00]

Done.

[ftang, 2016/04/29 22:37:00]

Done.

+  ADVANCED_LINK_CLICKED = 3,
+
+  // User check the "always translate" checkbox
+  ALWAYS_TRANSLATE_CHECKED = 4,
+
+  // User uncheck the "always translate" checkbox
+  ALWAYS_TRANSLATE_UNCHECKED = 5,
+
+  // User select the "Nope" in option menu
+  NOPE_MENU_CLICKED = 6,
+
+  // User select the "Never translate language" in option menu
+  NEVER_TRANSLATE_LANGUAGE_MENU_CLICKED = 7,
+
+  // User select the "Never translate this site" in option menu
+  NEVER_TRANSLATE_SITE_MENU_CLICKED = 8,
+
+  // User click "Translate" button
+  TRANSLATE_BUTTON_CLICKED = 9,
+
+  // User click the "Done" button
+  DONE_BUTTON_CLICKED = 10,
+
+  // User click the "Cancel" button
+  CANCEL_BUTTON_CLICKED = 11,
+
+  // User click the "Closed" [X] button

[msw, 2016/04/29 20:00:00]

nit: s/Closed/Close/ and s/[X]/(x)/

+  CLOSE_BUTTON_CLICKED = 12,
+
+  // User click the "Try Again" button
+  TRY_AGAIN_BUTTON_CLICKED = 13,
+
+  // User click the "Show Original" button
+  SHOW_ORIGINAL_BUTTON_CLICKED = 14,
+
+  // User click the "Setting" link
+  SETTING_LINK_CLICKED = 15,
+
+  // User change the "Source language"
+  SOURCE_LANGUAGE_MENU_CLICKED = 16,
+
+  // User change the "Target language"
+  TARGET_LANGUAGE_MENU_CLICKED = 17 ,

[msw, 2016/04/29 20:00:00]

nit: remove the space before the comma.

+
+  TRANSLATE_BUBBLE_UI_EVENT_MAX
+};
+}  // namespace translate
+
 // The class which manages the transition of the view state of the Translate
 // bubble.
 class TranslateBubbleViewStateTransition {
  public:
   explicit TranslateBubbleViewStateTransition(
       TranslateBubbleModel::ViewState view_state);
 
   TranslateBubbleModel::ViewState view_state() const { return view_state_; }
 
   // Transitions the view state.
   void SetViewState(TranslateBubbleModel::ViewState view_state);
 
   // Goes back from the 'Advanced' view state.
   void GoBackFromAdvanced();
 
  private:
   // The current view type.
   TranslateBubbleModel::ViewState view_state_;
 
   // The view type. When the current view type is not 'Advanced' view, this is
   // equivalent to |view_state_|. Otherwise, this is the previous view type
   // before the user opens the 'Advanced' view. This is used to navigate when
   // pressing 'Cancel' button on the 'Advanced' view.
   TranslateBubbleModel::ViewState view_state_before_advanced_view_;
 
   DISALLOW_COPY_AND_ASSIGN(TranslateBubbleViewStateTransition);
 };
 
 #endif  // CHROME_BROWSER_UI_TRANSLATE_TRANSLATE_BUBBLE_VIEW_STATE_TRANSITION_H_