add local caching for skia draws

pdfium.gyp

 # Copyright 2015 PDFium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'variables': {
     'chromium_code': 1,
 
     'variables': {
       'clang_use_pdfium_plugins%': 0,
@@ skipping 926 matching lines @@
       'conditions': [
         ['pdf_enable_xfa==1', {
           'sources': [
             'xfa/fde/css/fde_cssdatatable.cpp',
             'xfa/fde/xml/fde_xml_imp_unittest.cpp',
             'xfa/fxbarcode/pdf417/BC_PDF417HighLevelEncoder_unittest.cpp',
             'xfa/fxfa/app/xfa_textlayout_unittest.cpp',
             'xfa/fxfa/parser/xfa_utils_imp_unittest.cpp',
           ],
         }],
+        ['pdf_use_skia==1', {
+          'sources': [
+            'core/fxge/skia/fx_skia_device_unittest.cpp',
+          ],
+        }],
         ['pdf_enable_v8==1', {
           'include_dirs': [
             '<(DEPTH)/v8',
             '<(DEPTH)/v8/include',
           ],
           'sources': [
             'fpdfsdk/javascript/public_methods_unittest.cpp',
           ],
         }],
       ],
@@ skipping 101 matching lines @@
             'fpdfsdk/fpdfxfa/include/fpdfxfa_app.h',
             'fpdfsdk/fpdfxfa/include/fpdfxfa_doc.h',
             'fpdfsdk/fpdfxfa/include/fpdfxfa_page.h',
             'fpdfsdk/fpdfxfa/include/fpdfxfa_util.h',
           ],
         },
       ]
     }],
   ]
 }