Enable chromium_code=1 on Windows

Source/config.gyp

Index: Source/config.gyp
diff --git a/Source/config.gyp b/Source/config.gyp
index 52da069c6d3ef4155e06adf19c86eb2c2f79ade3..3e62c10bf67a3e0410d303f1279c65e795d7e471 100644
--- a/Source/config.gyp
+++ b/Source/config.gyp
@@ -43,8 +43,11 @@
         '..',
       ],
       'msvs_disabled_warnings': [
-        4138, 4244, 4291, 4305, 4344, 4355, 4521, 4099,
+        4138, 4244, 4291, 4305, 4344, 4355, 4521, 4099, 4800, 4996,

[scottmg, 2013/11/06 04:40:48]

4800 is "forcing value to bool 'true' or 'false' (performance warning)"

4996 is "using POSIX name instead of ISO name" (in this case strdup instead of
_strdup).

Both seem silly to me. We should probably turn them off in build/common.gypi
too.

[Peter Kasting, 2013/11/06 07:20:02]

I don't think they're huge deals, but what would we lose by simply fixing them? 
The first can be fixed (where existing code is correct) using any of
"static_cast<bool>(...)", "... != 0", or "!!...", and seems like it could
potentially catch cases where people unintentionally use a numeric value as a
boolean one.  For the second, does using thee ISO names create portability
problems?

(Note: We could fix these in a separate CL, if there are a lot.)

       ],
+      'variables': {
+        'chromium_code': 1,

[Peter Kasting, 2013/11/06 07:20:02]

This doesn't go into the variables section at the top?

+      },
       'conditions': [
         ['OS=="win" and component=="shared_library"', {
           'defines': [
@@ -89,12 +92,6 @@
           # timesNewRoman.unstatic.3258 and colorTransparent.unstatic.4879.
           'cflags': ['-Wno-uninitialized'],
         }],
-        ['OS!="win"', {
-          # TODO: Turn this on on all platforms, http://crbug.com/312287
-          'variables': {
-            'chromium_code': 1,
-          },
-        }],
         ['clang==1', {
           'cflags': ['-Wglobal-constructors'],
           'xcode_settings': {