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

pdfium.gyp

Index: pdfium.gyp
diff --git a/pdfium.gyp b/pdfium.gyp
index 0ac04715e456155a2f59eb3714ef8ef9358ad0d3..0313280e440c3d4c0f6a67dea8b4ed182702f2bc 100644
--- a/pdfium.gyp
+++ b/pdfium.gyp
@@ -308,6 +308,12 @@
       'include_dirs': [
       ],
       'ldflags': [ '-L<(PRODUCT_DIR)',],
+      'msvs_settings': {
+        'VCCLCompilerTool': {
+          # Unresolved warnings in fx_codec_jpx_opj.cpp

[scottmg, 2015/01/06 19:48:53]

Would be good to add a crbug here that contains the list of warnings, and why
they haven't/can't be fixed easily.

[brucedawson, 2015/01/06 21:01:17]

Done.

+          'WarnAsError': 'false',
+        },
+      },
       'sources': [
         'core/include/fxcodec/fx_codec.h',
         'core/include/fxcodec/fx_codec_def.h',