Convert some GN test support targets to static libs.

components/toolbar/BUILD.gn

 # 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.
 
 import("//build/config/ui.gni")
 
-source_set("toolbar") {
+static_library("toolbar") {
   sources = [
     "toolbar_model.cc",
     "toolbar_model.h",
     "toolbar_model_delegate.h",
     "toolbar_model_impl.cc",
     "toolbar_model_impl.h",
   ]
 
   deps = [
     "//base",
     "//components/google/core/browser",
     "//components/prefs",
     "//components/resources",
     "//components/security_state",
     "//components/strings",
     "//components/url_formatter",
     "//net",
     "//ui/base",
     "//ui/gfx",
     "//url",
   ]
 }
 
-source_set("test_support") {
+static_library("test_support") {
   testonly = true
 
   sources = [
     "test_toolbar_model.cc",
     "test_toolbar_model.h",
   ]
 
   deps = [
     ":toolbar",
     "//base",
     "//components/resources",
     "//ui/gfx",
   ]
 
   if (toolkit_views) {
     # Needed to get the TOOLKIT_VIEWS define.
     deps += [ "//ui/views" ]
   }
 }