Move CPDF_Annot and CPDF_AnnotList to their own header.

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,
     'pdf_use_skia%': 0,
     'pdf_enable_v8%': 1,
     'pdf_enable_xfa%': 0, # Set to 1 by standalone.gypi in a standalone build.
@@ skipping 183 matching lines @@
         'core/fpdfdoc/cpvt_sectioninfo.cpp',
         'core/fpdfdoc/cpvt_sectioninfo.h',
         'core/fpdfdoc/cpvt_wordinfo.cpp',
         'core/fpdfdoc/cpvt_wordinfo.h',
         'core/fpdfdoc/csection.cpp',
         'core/fpdfdoc/csection.h',
         'core/fpdfdoc/ctypeset.cpp',
         'core/fpdfdoc/ctypeset.h',
         'core/fpdfdoc/doc_action.cpp',
         'core/fpdfdoc/doc_annot.cpp',
+        'core/fpdfdoc/doc_annot.h',
         'core/fpdfdoc/doc_basic.cpp',
         'core/fpdfdoc/doc_bookmark.cpp',
         'core/fpdfdoc/doc_form.cpp',
         'core/fpdfdoc/doc_formcontrol.cpp',
         'core/fpdfdoc/doc_formfield.cpp',
         'core/fpdfdoc/doc_link.cpp',
         'core/fpdfdoc/doc_metadata.cpp',
         'core/fpdfdoc/doc_ocg.cpp',
         'core/fpdfdoc/doc_tagged.cpp',
         'core/fpdfdoc/doc_utils.cpp',
@@ skipping 850 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',
           ],
         },
       ]
     }],
   ]
 }