Add pdf layer code for PDFium XFA module

pdf/pdf.gyp

 {
   'variables': {
     'chromium_code': 1,
     'pdf_engine%': 0,  # 0 PDFium
+    'pdf_use_xfa%': 0,

[Lei Zhang, 2014/11/05 22:45:09]

You need to make the corresponding change in pdf/BUILD.gn

[Bo Xu, 2014/11/06 01:26:20]

Done.

   },
   'target_defaults': {
     'cflags': [
       '-fPIC',
     ],
   },
   'targets': [
     {
       'target_name': 'pdf',
       'type': 'loadable_module',
@@ skipping 47 matching lines @@
         'preview_mode_client.cc',
         'preview_mode_client.h',
         'resource.h',
         'resource_consts.h',
         'thumbnail_control.cc',
         'thumbnail_control.h',
         '../chrome/browser/chrome_page_zoom_constants.cc',
         '../content/common/page_zoom.cc',
       ],
       'conditions': [
+        ['pdf_use_xfa==1', {
+          'defines': ['_TEST_XFA_'],

[Tom Sepez, 2014/11/05 22:44:47]

nit: the #define should be PDF_USE_XFA for consistency.

[Bo Xu, 2014/11/06 01:26:20]

Done.

+        }],
         ['pdf_engine==0', {
           'sources': [
             'pdfium/pdfium_assert_matching_enums.cc',
             'pdfium/pdfium_engine.cc',
             'pdfium/pdfium_engine.h',
             'pdfium/pdfium_mem_buffer_file_read.cc',
             'pdfium/pdfium_mem_buffer_file_read.h',
             'pdfium/pdfium_mem_buffer_file_write.cc',
             'pdfium/pdfium_mem_buffer_file_write.h',
             'pdfium/pdfium_page.cc',
@@ skipping 109 matching lines @@
                 '--input_symbol', '<(PRODUCT_DIR)/pdf.dll.pdb',
                 '--destination_dir', '<(dest_dir)',
               ],
             },
           ],
         },
       ],
     }],  # OS=="win" and fastbuild==0 and target_arch=="ia32" and syzyasan==1
   ],
 }