Add flag to show toolkit-views dialogs on Mac, start with HTTP-Auth.

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index e2f011574cb00d2087cedeb6c1b0fbb6c2c7e5b9..61610a9d53e02cb7ba1e04cbccda9a2a9b5955ab 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -1270,6 +1270,10 @@ const char kEnableAppWindowCycling[] = "enable-app-window-cycling";
 const char kEnableMacViewsNativeAppWindows[] =
     "enable-mac-views-native-app-windows";
 
+// Causes Chrome to use an equivalent toolkit-views version of a browser dialog
+// when available, rather than a Cocoa one.
+const char kEnableToolkitViewsDialogsMac[] = "enable-toolkit-views-dialogs-mac";
+
 // Enables Translate experimental new UX which replaces the infobar.
 const char kEnableTranslateNewUX[]         = "enable-translate-new-ux";