Only SolidBrush types are created, remove other brushes.

BUILD.gn

 # Copyright 2016 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_overrides/v8.gni")
 import("//testing/test.gni")
 import("pdfium.gni")
 
 config("pdfium_config") {
   cflags = []
@@ skipping 888 matching lines @@
       "xfa/fde/css/fde_cssdatatable.h",
       "xfa/fde/css/fde_cssdeclaration.cpp",
       "xfa/fde/css/fde_cssdeclaration.h",
       "xfa/fde/css/fde_cssstyleselector.cpp",
       "xfa/fde/css/fde_cssstyleselector.h",
       "xfa/fde/css/fde_cssstylesheet.cpp",
       "xfa/fde/css/fde_cssstylesheet.h",
       "xfa/fde/css/fde_csssyntax.cpp",
       "xfa/fde/css/fde_csssyntax.h",
       "xfa/fde/fde_brush.h",
-      "xfa/fde/fde_devbasic.cpp",
-      "xfa/fde/fde_devbasic.h",
       "xfa/fde/fde_gedevice.cpp",
       "xfa/fde/fde_gedevice.h",
       "xfa/fde/fde_geobject.cpp",
       "xfa/fde/fde_geobject.h",
       "xfa/fde/fde_image.h",
       "xfa/fde/fde_iterator.cpp",
       "xfa/fde/fde_iterator.h",
-      "xfa/fde/fde_object.cpp",
       "xfa/fde/fde_object.h",
       "xfa/fde/fde_path.h",
       "xfa/fde/fde_pen.h",
       "xfa/fde/fde_render.cpp",
       "xfa/fde/fde_render.h",
       "xfa/fde/fde_renderdevice.h",
       "xfa/fde/tto/fde_textout.cpp",
       "xfa/fde/tto/fde_textout.h",
       "xfa/fde/xml/fde_xml.h",
       "xfa/fde/xml/fde_xml_imp.cpp",
@@ skipping 795 matching lines @@
       "//v8:v8_libplatform",
     ]
     include_dirs += [
       "//v8",
       "//v8/include",
     ]
     configs += [ "//v8:external_startup_data" ]
   }
   configs += [ ":pdfium_config" ]
 }