[Chrome OS MD] Implement accessibility detailed view for the MD Ash system menu

ash/common/system/tray_accessibility.h

Index: ash/common/system/tray_accessibility.h
diff --git a/ash/common/system/tray_accessibility.h b/ash/common/system/tray_accessibility.h
index 1c280e317a957554a19e5b9348fcde0a22812e23..8e4a3158f14e397f5efd12f2b59db5d415e4faa3 100644
--- a/ash/common/system/tray_accessibility.h
+++ b/ash/common/system/tray_accessibility.h
@@ -21,6 +21,10 @@ namespace chromeos {
 class TrayAccessibilityTest;
 }
 
+namespace gfx {
+struct VectorIcon;
+}
+
 namespace views {
 class Button;
 class ImageView;
@@ -51,6 +55,9 @@ class AccessibilityPopupView : public TrayNotificationView {
 class AccessibilityDetailedView : public TrayDetailsView,
                                   public ShellObserver {
  public:
+  // Create the detailed view of accessibility tray. Note that the help option

[tdanderson, 2016/09/19 23:32:27]

Generally a comment directly above a constructor should be about something
specific to that constructor.

Consider removing the first sentence and, optionally, adding class-level
documentation (above line 55).

As for the second sentence, I think a better place for it would be above
AppendHelpEntries() on line 73. You could just add "Only used for non-MD" to the
comment that's already there.

[yiyix, 2016/09/21 17:10:48]

I put the first sentence as a class description to the
AccessibilityDetailedView; and add the second sentence to AppendHelpEntries.
Thanks.

+  // row will be shown in non-MD version only and it will be integrated to the
+  // title row in MD.
   AccessibilityDetailedView(SystemTrayItem* owner, LoginStatus login);
   ~AccessibilityDetailedView() override {}
 
@@ -66,9 +73,11 @@ class AccessibilityDetailedView : public TrayDetailsView,
   // Add help entries.
   void AppendHelpEntries();
 
+  // Helper function to create entries in the detailed accessibility view.

[tdanderson, 2016/09/19 23:32:27]

nit: Maybe mention that the |icon| parameter is only used for MD.

[yiyix, 2016/09/21 17:10:48]

Done.

   HoverHighlightView* AddScrollListItem(const base::string16& text,
                                         bool highlight,
-                                        bool checked);
+                                        bool checked,
+                                        const gfx::VectorIcon& icon);
 
   views::View* spoken_feedback_view_;
   views::View* high_contrast_view_;