Enable profiling options to be selectively enabled for a given build

Review URL: https://codereview.appspot.com/6858089

git-svn-id: http://skia.googlecode.com/svn/trunk@6598 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gyp/common_variables.gypi b/gyp/common_variables.gypi
index 974e93b..1c900c5 100644
--- a/gyp/common_variables.gypi
+++ b/gyp/common_variables.gypi
@@ -86,6 +86,7 @@
       'skia_directwrite%': 0,
       'skia_gpu%': 1,
       'skia_osx_sdkroot%': 'macosx',
+      'skia_profile_enabled%': 0,
     },
 
     # Re-define all variables defined within the level-2 'variables' dict,
@@ -104,6 +105,7 @@
     'skia_directwrite%': '<(skia_directwrite)',
     'skia_gpu%': '<(skia_gpu)',
     'skia_osx_sdkroot%': '<(skia_osx_sdkroot)',
+    'skia_profile_enabled%': '<(skia_profile_enabled)',
     'skia_static_initializers%': '<(skia_static_initializers)',
     'ios_sdk_version%': '6.0',