MediaRouterAction: Only observe Media Routes when there is a local route.

chrome/browser/ui/toolbar/media_router_action.cc

Index: chrome/browser/ui/toolbar/media_router_action.cc
diff --git a/chrome/browser/ui/toolbar/media_router_action.cc b/chrome/browser/ui/toolbar/media_router_action.cc
index 4d2ca8d54daa45488831eb6e01a582dddc6fa63f..7a9e6ff3e59ccd6cdae6281c943d29167f78098b 100644
--- a/chrome/browser/ui/toolbar/media_router_action.cc
+++ b/chrome/browser/ui/toolbar/media_router_action.cc
@@ -25,9 +25,31 @@
 
 using media_router::MediaRouterDialogControllerImpl;
 
+MediaRouterAction::ActionMediaRoutesObserver::ActionMediaRoutesObserver(
+    media_router::MediaRouter* router,
+    MediaRouterAction* action)
+    : MediaRoutesObserver(router),
+      action_(action) {
+  DCHECK(action);
+}
+
+MediaRouterAction::ActionMediaRoutesObserver::~ActionMediaRoutesObserver() {
+}
+
+void MediaRouterAction::ActionMediaRoutesObserver::OnRoutesUpdated(
+    const std::vector<media_router::MediaRoute>& routes) {
+  bool has_local_route =
+      std::find_if(routes.begin(), routes.end(),
+                   [](const media_router::MediaRoute& route) {
+                      return route.is_local(); }) !=
+      routes.end();
+
+  action_->SetHasLocalRoute(has_local_route);

[imcheng, 2015/10/01 18:46:50]

there should be a comment that |this| will be deleted beyond this point if
has_local_route is false.

[apacible, 2015/10/01 23:21:47]

Done (after moving this to MediaRouterMojoImpl).

+}
+
 MediaRouterAction::MediaRouterAction(Browser* browser)
     : media_router::IssuesObserver(GetMediaRouter(browser)),
-      media_router::MediaRoutesObserver(GetMediaRouter(browser)),
+      media_router::LocalMediaRoutesObserver(GetMediaRouter(browser)),
       media_router_active_icon_(
           ui::ResourceBundle::GetSharedInstance()
               .GetImageNamed(IDR_MEDIA_ROUTER_ACTIVE_ICON)),
@@ -42,6 +64,8 @@ MediaRouterAction::MediaRouterAction(Browser* browser)
       has_local_route_(false),
       delegate_(nullptr),
       browser_(browser),
+      routes_observer_(new ActionMediaRoutesObserver(

[imcheng, 2015/10/01 18:46:50]

So we are still sending a routes query on construction. I want to see if we can
delay that until we know there is a local route. In fact, we can probably only
depend on LocalMediaRoutesObserver in this class. We may have to add an
HasLocalRoutes() to MediaRouter to determine the initial state.

[apacible, 2015/10/01 23:21:47]

Talked offline. Done.

+                           GetMediaRouter(browser), this)),
       platform_delegate_(MediaRouterActionPlatformDelegate::Create(browser)),
       contextual_menu_(browser),
       tab_strip_model_observer_(this),
@@ -51,6 +75,7 @@ MediaRouterAction::MediaRouterAction(Browser* browser)
 }
 
 MediaRouterAction::~MediaRouterAction() {
+  routes_observer_.reset();

[imcheng, 2015/10/01 18:46:50]

not needed?

[apacible, 2015/10/01 23:21:47]

Done.

 }
 
 std::string MediaRouterAction::GetId() const {
@@ -138,14 +163,10 @@ void MediaRouterAction::OnIssueUpdated(const media_router::Issue* issue) {
   MaybeUpdateIcon();
 }
 
-void MediaRouterAction::OnRoutesUpdated(
-    const std::vector<media_router::MediaRoute>& routes) {
-  has_local_route_ =
-      std::find_if(routes.begin(), routes.end(),
-                   [](const media_router::MediaRoute& route) {
-                      return route.is_local(); }) !=
-      routes.end();
-  MaybeUpdateIcon();
+void MediaRouterAction::OnLocalRouteCreated() {
+  if (!routes_observer_)
+    routes_observer_.reset(new ActionMediaRoutesObserver(
+        GetMediaRouter(browser_), this));
 }
 
 void MediaRouterAction::ActiveTabChanged(content::WebContents* old_contents,
@@ -167,6 +188,15 @@ void MediaRouterAction::OnPopupShown() {
     delegate_->OnPopupShown(true);
 }
 
+void MediaRouterAction::SetHasLocalRoute(bool has_local_route) {
+  has_local_route_ = has_local_route;
+
+  if (!has_local_route_)
+    routes_observer_.reset();
+
+  MaybeUpdateIcon();
+}
+
 void MediaRouterAction::UpdatePopupState() {
   MediaRouterDialogControllerImpl* controller =
       GetMediaRouterDialogController();