Use allSinks to find a sink in kFindSinkScript.

chrome/test/media_router/media_router_integration_browsertest.cc

Index: chrome/test/media_router/media_router_integration_browsertest.cc
diff --git a/chrome/test/media_router/media_router_integration_browsertest.cc b/chrome/test/media_router/media_router_integration_browsertest.cc
index 32a5e7de342edaa59860ce9dde37854c184687d2..9cf897cdfa58415bade22877f0929934151589e4 100644
--- a/chrome/test/media_router/media_router_integration_browsertest.cc
+++ b/chrome/test/media_router/media_router_integration_browsertest.cc
@@ -83,13 +83,15 @@ const char kGetRouteIdScript[] =
     "}"
     "domAutomationController.send('');";
 const char kFindSinkScript[] =
-    "var sinks = document.getElementById('media-router-container')."
-    "  shadowRoot.getElementById('sink-list').getElementsByTagName('span');"
-    "for (var i=0; i<sinks.length; i++) {"
-    "  if (sinks[i].textContent.trim() == '%s') {"
-    "    domAutomationController.send(true);"
-    "}}"
-    "domAutomationController.send(false);";
+    "try {"
+    "  var sinks = document.getElementById('media-router-container')."

[imcheng, 2017/02/09 18:18:31]

Why not do a null check? e.g.,

const sinkList = document
    .getElementById('media-router-container')
    .shadowRoot.getElementById('sink-list');
if (!sinkList)
  domAutomationController.send(false);

var sinks = sinkList.getElementsByTagName('span');
...

[cliffordcheng1, 2017/02/09 20:03:48]

Done.

+    "    shadowRoot.getElementById('sink-list').getElementsByTagName('span');"
+    "  for (var i=0; i<sinks.length; i++) {"
+    "    if (sinks[i].textContent.trim() == '%s') {"
+    "      domAutomationController.send(true);"
+    "  }}}"
+    "finally {"
+    "domAutomationController.send(false);}";
 const char kCheckDialogLoadedScript[] =
     "var container = document.getElementById('media-router-container');"
     "/** Wait until media router container is not undefined and "