[Media Router] Clean up issues related code.

chrome/browser/ui/toolbar/media_router_action.h

 // Copyright 2015 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_TOOLBAR_MEDIA_ROUTER_ACTION_H_
 #define CHROME_BROWSER_UI_TOOLBAR_MEDIA_ROUTER_ACTION_H_
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
+#include "base/optional.h"
 #include "base/scoped_observer.h"
 #include "chrome/browser/media/router/issues_observer.h"
 #include "chrome/browser/media/router/media_routes_observer.h"
 #include "chrome/browser/ui/tabs/tab_strip_model_observer.h"
 #include "chrome/browser/ui/toolbar/media_router_contextual_menu.h"
 #include "chrome/browser/ui/toolbar/toolbar_action_view_controller.h"
 #include "chrome/browser/ui/toolbar/toolbar_actions_bar.h"
 #include "chrome/browser/ui/toolbar/toolbar_actions_bar_observer.h"
 #include "ui/gfx/vector_icons_public.h"
 
@@ skipping 32 matching lines @@
   bool WantsToRun(content::WebContents* web_contents) const override;
   bool HasPopup(content::WebContents* web_contents) const override;
   void HidePopup() override;
   gfx::NativeView GetPopupNativeView() override;
   ui::MenuModel* GetContextMenu() override;
   bool ExecuteAction(bool by_user) override;
   void UpdateState() override;
   bool DisabledClickOpensMenu() const override;
 
   // media_router::IssuesObserver:
-  void OnIssueUpdated(const media_router::Issue* issue) override;
+  void OnIssue(const media_router::Issue& issue) override;
+  void OnIssuesCleared() override;
 
   // media_router::MediaRoutesObserver:
   void OnRoutesUpdated(const std::vector<media_router::MediaRoute>& routes,
                        const std::vector<media_router::MediaRoute::Id>&
                            joinable_route_ids) override;
 
   // ToolbarStripModelObserver:
   void ActiveTabChanged(content::WebContents* old_contents,
                         content::WebContents* new_contents,
                         int index,
@@ skipping 29 matching lines @@
   // Checks if the current icon of MediaRouterAction has changed. If so,
   // updates |current_icon_|.
   void MaybeUpdateIcon();
 
   gfx::VectorIconId GetCurrentIcon() const;
 
   // The current icon to show. This is updated based on the current issues and
   // routes since |this| is an IssueObserver and MediaRoutesObserver.
   gfx::VectorIconId current_icon_;
 
-  // The current issue shown in the Media Router WebUI. Can be null. It is set
-  // in OnIssueUpdated(), which is called by the IssueManager.
-  std::unique_ptr<media_router::Issue> issue_;
+  // The current issue shown in the Media Router WebUI, or not set if there are

[msw, 2016/12/13 18:45:39]

nit: this comment mentions OnIssueUpdated, which no longer exists. Consider:
"The current issue shown in the Media Router WebUI, set in OnIssue() and cleared
in OnIssuesCleared()." or similar.

[imcheng, 2016/12/13 19:22:47]

Done.

+  // no issues currently.
+  // Set in OnIssueUpdated(), which is called by the IssueManager.
+  base::Optional<media_router::IssueInfo> current_issue_;

[msw, 2016/12/13 18:45:39]

q: Just curious, why is base::Optional better than std::unique_ptr here?

[imcheng, 2016/12/13 19:22:47]

It's mostly identical in terms of how they're used here, so I will change it
back to unique_ptr to avoid extra #include.

 
   // Whether a local displayable active route exists.
   bool has_local_display_route_;
 
   // Whether the Media Router dialog is shown in the current tab.
   // This should only be updated in OnDialogShown() and OnDialogHidden().
   bool has_dialog_;
 
   ToolbarActionViewDelegate* delegate_;
 
   Browser* const browser_;
   ToolbarActionsBar* const toolbar_actions_bar_;
 
   // The delegate to handle platform-specific implementations.
   std::unique_ptr<MediaRouterActionPlatformDelegate> platform_delegate_;
 
   MediaRouterContextualMenu contextual_menu_;
 
   ScopedObserver<TabStripModel, TabStripModelObserver>
       tab_strip_model_observer_;
   ScopedObserver<ToolbarActionsBar, ToolbarActionsBarObserver>
       toolbar_actions_bar_observer_;
 
   base::WeakPtrFactory<MediaRouterAction> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaRouterAction);
 };
 
 #endif  // CHROME_BROWSER_UI_TOOLBAR_MEDIA_ROUTER_ACTION_H_