Adds a field trial to control Web API kill switches.

chrome/browser/permissions/permission_context_uma_util.h

Index: chrome/browser/permissions/permission_context_uma_util.h
diff --git a/chrome/browser/permissions/permission_context_uma_util.h b/chrome/browser/permissions/permission_context_uma_util.h
index 05130bacf2b397ac5a05d41fce0eff8fef34e9af..d4c362b4896d9f16af1541650ed8262f63a87c18 100644
--- a/chrome/browser/permissions/permission_context_uma_util.h
+++ b/chrome/browser/permissions/permission_context_uma_util.h
@@ -27,6 +27,7 @@ class PermissionContextUmaUtil {
                                   const GURL& requesting_origin);
   static void PermissionIgnored(ContentSettingsType permission,
                                 const GURL& requesting_origin);
+  static const std::string GetPermissionString(ContentSettingsType permission);

[mlamouri (slow - plz ping), 2015/10/09 12:07:54]

I don't think this needs to be part of the class. Are you using any member in
the implementation?

[kcarattini, 2015/10/12 03:58:06]

No, that's why it is static. None of the other methods declared here use member
variables (in fact there aren't any member variables), so I viewed this class as
a collection of related methods to do with PermissionContext. With that
definition, do you disagree that it should be part of the class?

 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PermissionContextUmaUtil);