[Media Router] Add P1 UMA metrics for Media Router.

chrome/browser/ui/cocoa/toolbar/media_router_action_platform_delegate_cocoa.mm

Index: chrome/browser/ui/cocoa/toolbar/media_router_action_platform_delegate_cocoa.mm
diff --git a/chrome/browser/ui/cocoa/toolbar/media_router_action_platform_delegate_cocoa.mm b/chrome/browser/ui/cocoa/toolbar/media_router_action_platform_delegate_cocoa.mm
index df034ace0213fbcdb30b299e249f346d31b196ad..fe9e8ffac42e57a431d3abe7a4fcbbefe3765ce0 100644
--- a/chrome/browser/ui/cocoa/toolbar/media_router_action_platform_delegate_cocoa.mm
+++ b/chrome/browser/ui/cocoa/toolbar/media_router_action_platform_delegate_cocoa.mm
@@ -28,7 +28,7 @@ MediaRouterActionPlatformDelegateCocoa::
     ~MediaRouterActionPlatformDelegateCocoa() {
 }
 
-void MediaRouterActionPlatformDelegateCocoa::CloseOverflowMenuIfOpen() {
+bool MediaRouterActionPlatformDelegateCocoa::CloseOverflowMenuIfOpen() {
   // TODO(apacible): This should be factored to share code with extension
   // actions.
   WrenchMenuController* wrenchMenuController =
@@ -36,6 +36,10 @@ void MediaRouterActionPlatformDelegateCocoa::CloseOverflowMenuIfOpen() {
           browserWindowControllerForWindow:
               browser_->window()->GetNativeWindow()]
           toolbarController] wrenchMenuController];
-  if ([wrenchMenuController isMenuOpen])
+  if ([wrenchMenuController isMenuOpen]) {

[Peter Kasting, 2015/10/23 23:48:51]

Nit: If you reverse this conditional you can avoid the {}.

[apacible, 2015/10/24 22:06:28]

Done.

     [wrenchMenuController cancel];
+    return true;
+  }
+
+  return false;
 }