Fix a warning in libtess in Release builds; define NDEBUG in Release on all
platforms.

BUG:  http://code.google.com/p/skia/issues/detail?id=456
Review URL:  http://codereview.appspot.com/5555054/



git-svn-id: http://skia.googlecode.com/svn/trunk@3076 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gyp/common_conditions.gypi b/gyp/common_conditions.gypi
index e18cbc1..99cabc9 100644
--- a/gyp/common_conditions.gypi
+++ b/gyp/common_conditions.gypi
@@ -84,7 +84,8 @@
             'cflags': ['-g']
           },
           'Release': {
-            'cflags': ['-O2']
+            'cflags': ['-O2'],
+            'defines': [ 'NDEBUG' ],
           },
         },
         'cflags': [
@@ -119,6 +120,7 @@
             'xcode_settings': {
               'GCC_OPTIMIZATION_LEVEL': '3',
             },
+            'defines': [ 'NDEBUG' ],
           },
         },
         'xcode_settings': {
@@ -161,7 +163,8 @@
             'cflags': ['-g']
           },
           'Release': {
-            'cflags': ['-O2']
+            'cflags': ['-O2'],
+            'defines': [ 'NDEBUG' ],
           },
         },
         'libraries': [