Resolve all but two VC++ build warnings in pdfium.

pdfium.gyp

 {
   'variables': {
     'pdf_use_skia%': 0,
   },
   'target_defaults': {
     'defines' : [
       'FT2_BUILD_LIBRARY',
       '_FPDFSDK_LIB',
       '_NO_GDIPLUS_',  # workaround text rendering issues on Windows
       'OPJ_STATIC',
@@ skipping 290 matching lines @@
         'core/src/fpdftext/unicodenormalization.cpp',
         'core/src/fpdftext/unicodenormalizationdata.cpp',
       ],
     },
     {
       'target_name': 'fxcodec',
       'type': 'static_library',
       'include_dirs': [
       ],
       'ldflags': [ '-L<(PRODUCT_DIR)',],
+      'msvs_settings': {
+        'VCCLCompilerTool': {
+          # Unresolved warnings in fx_codec_jpx_opj.cpp
+          # https://code.google.com/p/pdfium/issues/detail?id=100
+          'WarnAsError': 'false',

[Nico, 2015/06/09 15:51:39]

Please don't add WarnAsError: false anywhere, ever. We want a quiet build, and
WarnAsError makes it possible to add warning noise to the build.

Is this still needed? A build of Chromium seems to still be warning-free, and
this is built as part of Chromium, right?

+        },
+      },
       'sources': [
         'core/include/fxcodec/fx_codec.h',
         'core/include/fxcodec/fx_codec_def.h',
         'core/include/fxcodec/fx_codec_provider.h',
         'core/src/fxcodec/codec/codec_int.h',
         'core/src/fxcodec/codec/fx_codec.cpp',
         'core/src/fxcodec/codec/fx_codec_fax.cpp',
         'core/src/fxcodec/codec/fx_codec_flate.cpp',
         'core/src/fxcodec/codec/fx_codec_icc.cpp',
         'core/src/fxcodec/codec/fx_codec_jbig.cpp',
@@ skipping 491 matching lines @@
       ],
       'include_dirs': [
         '<(DEPTH)'
       ],
       'sources': [
         'core/src/fxcrt/fx_basic_bstring_unittest.cpp',
       ],
     },
   ],
 }