Match GN and GYP compilation warning flags

build_gyp/standalone.gypi

Index: build_gyp/standalone.gypi
diff --git a/build_gyp/standalone.gypi b/build_gyp/standalone.gypi
index f191c28e42677cec6e1fad1436443d052750d52f..1fa07dcc0f4d54cfaf6a50a51d03edbd59aee074 100644
--- a/build_gyp/standalone.gypi
+++ b/build_gyp/standalone.gypi
@@ -202,13 +202,6 @@
     },
     'msvs_disabled_warnings': [
       # ####
-      # This section is PDFium specific.

[Lei Zhang, 2016/05/27 23:49:20]

Can you leave this section here? We still refer to it on line 292.

[Wei Li, 2016/05/28 00:11:59]

sure.

-      # ####
-
-      # C4800: forcing value to bool 'true' or 'false' (performance warning)

[Lei Zhang, 2016/05/27 23:49:20]

Just mention this section is currently empty.

[Wei Li, 2016/05/28 00:11:59]

Done.

-      4800,
-
-      # ####
       # This section should match Chromium's build/common.gypi.
       # ####
 
@@ -479,6 +472,10 @@
             '-Wno-unused-variable',
           ],
         },
+        'msvs_disabled_warnings': [
+          # forcing value to bool 'true' or 'false' (performance warning)
+          4800,
+        ],
         'msvs_settings': {
           'VCCLCompilerTool': {
             'WarningLevel': '3',