Reflect the current state in Media Router Action icon.

chrome/browser/ui/toolbar/media_router_action.h

Index: chrome/browser/ui/toolbar/media_router_action.h
diff --git a/chrome/browser/ui/toolbar/media_router_action.h b/chrome/browser/ui/toolbar/media_router_action.h
index 6cc6073cf8ca7248525faab2f2efbcf26108f187..607e726da4fa96b32969d9f5ca18bb2b65b83781 100644
--- a/chrome/browser/ui/toolbar/media_router_action.h
+++ b/chrome/browser/ui/toolbar/media_router_action.h
@@ -5,6 +5,8 @@
 #ifndef CHROME_BROWSER_UI_TOOLBAR_MEDIA_ROUTER_ACTION_H_
 #define CHROME_BROWSER_UI_TOOLBAR_MEDIA_ROUTER_ACTION_H_
 
+#include "chrome/browser/media/router/issues_observer.h"
+#include "chrome/browser/media/router/media_routes_observer.h"
 #include "chrome/browser/ui/toolbar/media_router_contextual_menu.h"
 #include "chrome/browser/ui/toolbar/toolbar_action_view_controller.h"
 
@@ -17,7 +19,9 @@ class MediaRouterDialogController;
 
 // The class for the Media Router component action that will be shown in
 // the toolbar.
-class MediaRouterAction : public ToolbarActionViewController {
+class MediaRouterAction : public ToolbarActionViewController,
+                          public media_router::IssuesObserver,
+                          public media_router::MediaRoutesObserver {
  public:
   explicit MediaRouterAction(Browser* browser);
   ~MediaRouterAction() override;
@@ -43,17 +47,52 @@ class MediaRouterAction : public ToolbarActionViewController {
   void UpdateState() override;
   bool DisabledClickOpensMenu() const override;
 
+  // media_router::IssuesObserver:
+  void OnIssueUpdated(const media_router::Issue* issue) override;
+
+  // media_router::MediaRoutesObserver:
+  void OnRoutesUpdated(const std::vector<media_router::MediaRoute>& routes)
+      override;
+
  private:
   // Returns a reference to the MediaRouterDialogController associated with
   // |delegate_|'s current WebContents. Guaranteed to be non-null.
   // |delegate_| and its current WebContents must not be null.
   media_router::MediaRouterDialogController* GetMediaRouterDialogController();
 
+  // Overridden by tests.
+  virtual media_router::MediaRouter* GetMediaRouter(Browser* browser);
+
+  // Checks if the current icon of MediaRouterAction has changed. If so,
+  // updates |current_icon_|.
+  void MaybeUpdateIcon();
+
+  const gfx::Image* GetCurrentIcon() const;
+
   const std::string id_;
   const base::string16 name_;
 
   // Cached icons.
-  gfx::Image media_router_idle_icon_;
+  // Indicates that the current Chrome profile is using at least one device.
+  const gfx::Image media_router_active_icon_;
+  // Indicates a failure, e.g. session launch failure.
+  const gfx::Image media_router_error_icon_;
+  // Indicates that the current Chrome profile is not using any devices.
+  // Devices may or may not be available.
+  const gfx::Image media_router_idle_icon_;
+  // Indicates there is a warning message.
+  const gfx::Image media_router_warning_icon_;
+
+  // The current icon to show. This is updated based on the current issues and
+  // routes since |this| is an IssueObserver and MediaRoutesObserver.
+  const gfx::Image* 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.
+  scoped_ptr<media_router::Issue> issue_;
+
+  // Whether a local active route exists.
+  bool has_local_route_;
 
   ToolbarActionViewDelegate* delegate_;