Remove unused CFFL_Notify.

pdfium.gyp

 {
   'variables': {
     'pdf_use_skia%': 0,
     'pdf_enable_v8%': 1,
     'conditions': [
       ['OS=="linux"', {
         'bundle_freetype%': 0,
       }, {  # On Android there's no system FreeType. On Windows and Mac, only a
             # few methods are used from it.
         'bundle_freetype%': 1,
@@ skipping 677 matching lines @@
       'target_name': 'formfiller',
       'type': 'static_library',
       'ldflags': [ '-L<(PRODUCT_DIR)',],
       'sources': [
         'fpdfsdk/include/formfiller/FFL_CBA_Fontmap.h',
         'fpdfsdk/include/formfiller/FFL_CheckBox.h',
         'fpdfsdk/include/formfiller/FFL_ComboBox.h',
         'fpdfsdk/include/formfiller/FFL_FormFiller.h',
         'fpdfsdk/include/formfiller/FFL_IFormFiller.h',
         'fpdfsdk/include/formfiller/FFL_ListBox.h',
-        'fpdfsdk/include/formfiller/FFL_Notify.h',
         'fpdfsdk/include/formfiller/FFL_PushButton.h',
         'fpdfsdk/include/formfiller/FFL_RadioButton.h',
         'fpdfsdk/include/formfiller/FFL_TextField.h',
         'fpdfsdk/include/formfiller/FFL_Utils.h',
         'fpdfsdk/include/formfiller/FormFiller.h',
         'fpdfsdk/src/formfiller/FFL_CBA_Fontmap.cpp',
         'fpdfsdk/src/formfiller/FFL_CheckBox.cpp',
         'fpdfsdk/src/formfiller/FFL_ComboBox.cpp',
         'fpdfsdk/src/formfiller/FFL_FormFiller.cpp',
         'fpdfsdk/src/formfiller/FFL_IFormFiller.cpp',
         'fpdfsdk/src/formfiller/FFL_ListBox.cpp',
-        'fpdfsdk/src/formfiller/FFL_Notify.cpp',
         'fpdfsdk/src/formfiller/FFL_PushButton.cpp',
         'fpdfsdk/src/formfiller/FFL_RadioButton.cpp',
         'fpdfsdk/src/formfiller/FFL_TextField.cpp',
         'fpdfsdk/src/formfiller/FFL_Utils.cpp',
       ],
     },
     {
       'target_name': 'pdfium_unittests',
       'type': 'executable',
       'dependencies': [
@@ skipping 84 matching lines @@
           ],
           'dependencies': [
             '<(DEPTH)/v8/tools/gyp/v8.gyp:v8',
             '<(DEPTH)/v8/tools/gyp/v8.gyp:v8_libplatform',
           ],
         }],
       ],
     },
   ],
 }