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 3cd1a7916650f82712407252a439c10596189239..dfb170368983e199d5c1081ab72668140921c0a0 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -1269,6 +1269,10 @@ 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 kEnableMacViewsDialogs[] = "enable-mac-views-dialogs";
+
 // Enables Translate experimental new UX which replaces the infobar.
 const char kEnableTranslateNewUX[]         = "enable-translate-new-ux";