GTTF: Make our handling of Windows pre-processor symbols more consistent.

For example, there are differences between unit_tests and browser_tests,
which cause ridiculous problems when moving a test between those.

We're using the symbols anyway, so let's centralize it for maintainability.

TEST=compile
BUG=none

Review URL: http://codereview.chromium.org/3173044

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@57555 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/build/common.gypi b/build/common.gypi
index b21398cd..0ed4972 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -529,6 +529,16 @@
          }],  # OS==win
         ],  # conditions for coverage
       }],  # coverage!=0
+      ['OS=="win"', {
+        'defines': [
+          '__STD_C',
+          '_CRT_SECURE_NO_DEPRECATE',
+          '_SCL_SECURE_NO_DEPRECATE',
+        ],
+        'include_dirs': [
+          '<(DEPTH)/third_party/wtl/include',
+        ],
+      }],  # OS==win
     ],  # conditions for 'target_defaults'
     'target_conditions': [
       ['chromium_code==0', {