Add support for webapk without runtimeHost

chrome/android/webapk/strings/android_webapk_strings.grd

Index: chrome/android/webapk/strings/android_webapk_strings.grd
diff --git a/chrome/android/webapk/strings/android_webapk_strings.grd b/chrome/android/webapk/strings/android_webapk_strings.grd
index 84613665384cbd66d8c4beb659fc08d75f055f5d..a95e30333c67a6952cf218f0afb9ead257c452db 100644
--- a/chrome/android/webapk/strings/android_webapk_strings.grd
+++ b/chrome/android/webapk/strings/android_webapk_strings.grd
@@ -100,7 +100,9 @@
       <message name="IDS_CHOOSE_HOST_BROWSER" desc="Content for the host browser picker dialog, which is used to ask users to pick a browser to launch the installed WebAPK.">
         Please select the browser you'd like to use to run <ph name="WEBAPK_SITE">%1$s<ex>Housing.com</ex></ph>
       </message>
-      
+      <message name="IDS_CHOOSE_HOST_BROWSER_DIALOG_CANCEL" desc="Text for the cancel button on the dialog. ">

[pkotwicz, 2017/05/25 02:59:09]

Maybe rename this to IDS_CHOOSE_HOST_BROWSER_DIALOG_QUIT to match
ChooseHostBrowserDialogFragment#DialogListener

[Xi Han, 2017/05/25 19:29:33]

Done.

+        Quit
+      </message>
     </messages>
   </release>
 </grit>