Clean up poppler code.

gyp/dm.gyp

 # GYP for "dm" (Diamond Master, a.k.a Dungeon master, a.k.a GM 2).
 {
     'includes': [ 'apptype_console.gypi' ],
 
     'targets': [{
         'target_name': 'dm',
         'type': 'executable',
         'includes': [
           'dm.gypi',
         ],
         'conditions': [
           ['skia_android_framework', {
               'libraries': [
                   '-lskia',
                   '-landroid',
                   '-lgui',
                   '-lhwui',
                   '-lutils',
               ],
               'include_dirs': [
                   '../../../frameworks/base/libs/hwui/',
                   '../../../frameworks/native/include/',
               ],
               'sources': [
                 '../dm/DMSrcSinkAndroid.cpp',
               ],
           }],
-          ['skia_poppler_enabled', {
-              'sources':      [ '../src/utils/SkPDFRasterizer.cpp' ],
-              'defines':      [ 'SK_BUILD_POPPLER' ],
-              'dependencies': [ 'poppler.gyp:*' ],
-          }],
         ],
     }]
 }