Simplify the text in the external protocol confirmation dialog.

chrome/browser/external_protocol/external_protocol_handler.cc

Index: chrome/browser/external_protocol/external_protocol_handler.cc
diff --git a/chrome/browser/external_protocol/external_protocol_handler.cc b/chrome/browser/external_protocol/external_protocol_handler.cc
index 540ffbafe93572eab5b343b4c2dabcd895ca1907..70ea49533d3c675ab2f6eeffc4f7e1d1efb678f4 100644
--- a/chrome/browser/external_protocol/external_protocol_handler.cc
+++ b/chrome/browser/external_protocol/external_protocol_handler.cc
@@ -131,6 +131,10 @@ void OnDefaultProtocolClientWorkerFinished(
 }  // namespace
 
 // static
+const char ExternalProtocolHandler::kRememberCheckedHistogram[] =
+    "ExternalProtocolDialog.RememberCheckbox";

[meacer, 2016/10/04 01:28:56]

I think it'll be nicer if the UMA code was moved here instead of exposing this
static:

void ExternalProtocolHandler::RecordMetrics(bool selected) {
  UMA_HISTOGRAM_SPARSE_SLOWLY(kRememberCheckedHistogram,
                              selected);
}

[dominickn, 2016/10/04 12:37:01]

Done.

+
+// static
 void ExternalProtocolHandler::PrepopulateDictionary(
     base::DictionaryValue* win_pref) {
   static bool is_warm = false;