Convert some GN test support targets to static libs.

ui/gl/BUILD.gn

 # Copyright 2014 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/linux/pkg_config.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 use_egl = is_win || is_android || is_linux
 use_glx = use_x11
@@ skipping 272 matching lines @@
 
     libs = [ "android" ]
 
     deps += [
       ":gl_jni_headers",
       "//ui/android:ui_java",
     ]
   }
 }
 
-source_set("gl_unittest_utils") {
+static_library("gl_unittest_utils") {
   testonly = true
   sources = [
     "gl_bindings_autogen_mock.cc",
     "gl_bindings_autogen_mock.h",
     "gl_mock.cc",
     "gl_mock.h",
     "gl_mock_autogen_gl.h",
     "gpu_timing_fake.cc",
     "gpu_timing_fake.h",
   ]
 
   configs += [ "//third_party/khronos:khronos_headers" ]
 
   deps = [
     ":gl",
     "//testing/gmock",
     "//testing/gtest",
   ]
 }
 
-source_set("test_support") {
+static_library("test_support") {
   testonly = true
   sources = [
     "test/gl_image_test_support.cc",
     "test/gl_image_test_support.h",
     "test/gl_image_test_template.h",
     "test/gl_surface_test_support.cc",
     "test/gl_surface_test_support.h",
     "test/gl_test_helper.cc",
     "test/gl_test_helper.h",
   ]
@@ skipping 89 matching lines @@
     sources = [
       "../android/java/src/org/chromium/ui/gl/SurfaceTextureListener.java",
       "../android/java/src/org/chromium/ui/gl/SurfaceTexturePlatformWrapper.java",
     ]
     public_deps = [
       ":surface_jni_headers",
     ]
     jni_package = "ui/gl"
   }
 }