Add effects/core.gypi to 'sources' to make them appear in VS projects

Review URL: https://codereview.appspot.com/6493075/



git-svn-id: http://skia.googlecode.com/svn/trunk@5384 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gyp/effects.gyp b/gyp/effects.gyp
index 7ea732a..b3c5bb6 100644
--- a/gyp/effects.gyp
+++ b/gyp/effects.gyp
@@ -18,6 +18,9 @@
       'dependencies': [
         'core.gyp:core',
       ],
+      'sources': [
+        'effects.gypi', # Makes the gypi appear in IDEs (but does not modify the build).
+      ],
       'conditions': [
         ['skia_gpu == 1', {
           'include_dirs': [