[Media Router WebUI] Rename close route event in html

The event name used in media_router_container.html for closing routes
was not renamed by the previous change.

BUG=614144
R=apacible@chromium.org
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2036383002
Cr-Commit-Position: refs/heads/master@{#397792}

chrome/browser/resources/media_router/elements/media_router_container/media_router_container.html

@@ -87,7 +87,7 @@
         <route-details id="route-details" route="[[currentRoute_]]"
             available-cast-modes="[[computeAvailableCastModesForRoute_(currentRoute_)]]"
             replace-route-available="[[!currentLaunchingSinkId_]]"
-            on-close-route-click="onCloseRoute_"
+            on-close-route="onCloseRoute_"
             on-replace-route-click="onReplaceRouteClick_">
         </route-details>
       </template>