Use standard new-window and new-private-window action names in desktop file

When Chrome uses the non-standard NewWindow action, there is a
duplicated entry in GNOME shell: one is the shell's built-in new
window action, and the other is Chrome's.

Using new-window instead solves this issue.

Also, change NewPrivateWindow to use new-private-window as well, since
this is what firefox does.

BUG=783963
R=thestig@chromium.org

Change-Id: I9747a402358089bfa297cf32f29c50c2a1f53035
Reviewed-on: https://chromium-review.googlesource.com/764557Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/master@{#516101}

chrome/installer/linux/common/desktop.template

@@ -111,9 +111,9 @@ Icon=@@PACKAGE@@
 Type=Application
 Categories=Network;WebBrowser;
 MimeType=text/html;text/xml;application/xhtml_xml;image/webp;x-scheme-handler/http;x-scheme-handler/https;x-scheme-handler/ftp;
-Actions=NewWindow;NewPrivateWindow;
+Actions=new-window;new-private-window;
 
-[Desktop Action NewWindow]
+[Desktop Action new-window]
 Name=New Window
 Name[am]=አዲስ መስኮት
 Name[ar]=نافذة جديدة
@@ -167,7 +167,7 @@ Name[zh_CN]=新建窗口
 Name[zh_TW]=開新視窗
 Exec=/usr/bin/@@USR_BIN_SYMLINK_NAME@@
 
-[Desktop Action NewPrivateWindow]
+[Desktop Action new-private-window]
 Name=New Incognito Window
 Name[ar]=نافذة جديدة للتصفح المتخفي
 Name[bg]=Нов прозорец „инкогнито“