Remove log filtering and add stringsetflag.

common/logging/fields_test.go

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package logging
 
 import (
         "errors"
         "fmt"
         "sort"
@@ skipping 110 matching lines @@
                 So(fm, ShouldHaveSameTypeAs, Fields(nil))
 
                 Convey(`Returns an augmented Fields when Copied with a populated Fields.`, func() {
                         other := Fields{
                                 ErrorKey: errors.New("err"),
                         }
                         So(fm.Copy(other), ShouldResemble, Fields{"foo": "bar", "baz": "qux", ErrorKey: errors.New("err")})
                 })
 
                 Convey(`Has a String representation: {"baz":"qux", "foo":"bar"}`, func() {
-                        So(fm.FieldString(false), ShouldEqual, `{"baz":"qux", "foo":"bar"}`)
-                })
-
-                Convey(`With a FilterOn key`, func() {
-                        fm = fm.Copy(Fields{
-                                FilterOnKey: "test",
-                        })
-
-                        Convey(`Has a pruned String representation: {"baz":"qux", "foo":"bar"}`, func() {
-                                So(fm.FieldString(true), ShouldEqual, `{"baz":"qux", "foo":"bar"}`)
-                        })
+                        So(fm.String(), ShouldEqual, `{"baz":"qux", "foo":"bar"}`)
                 })
         })
 }
 
 func TestContextFields(t *testing.T) {
         Convey(`An empty Context`, t, func() {
                 c := context.Background()
 
                 Convey(`Has no Fields.`, func() {
                         So(GetFields(c), ShouldBeNil)
@@ skipping 17 matching lines @@
 
                                 So(GetFields(c), ShouldResemble, Fields{
                                         "foo":   "override",
                                         "baz":   "qux",
                                         "error": errors.New("failure"),
                                 })
                         })
                 })
         })
 }