Handle ctrl + shift + left click on links in PDF.

pdf/pdf.gyp

 {
   'variables': {
     'chromium_code': 1,
     'pdf_enable_xfa%': 0,
     'pdf_engine%': 0,  # 0 PDFium
   },
   'targets': [
     {
       'target_name': 'pdf',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
         '../gin/gin.gyp:gin',
         '../net/net.gyp:net',
         '../ppapi/ppapi.gyp:ppapi_cpp_objects',
         '../ppapi/ppapi.gyp:ppapi_internal_module',
+        '../ui/base/ui_base.gyp:ui_base',
       ],
       'ldflags': [ '-L<(PRODUCT_DIR)',],
       'sources': [
         'chunk_stream.h',
         'chunk_stream.cc',
         'document_loader.h',
         'document_loader.cc',
         'draw_utils.cc',
         'draw_utils.h',
         'out_of_process_instance.cc',
@@ skipping 35 matching lines @@
            ]
         }],
         ['OS=="win"', {
           # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
           'msvs_disabled_warnings': [ 4267, ],
         }],
       ],
     },
   ],
 }