mac DumpRenderTree: Include missingImage.png

BUG=http://wkb.urg/93186
TBR=tony

Review URL: https://chromiumcodereview.appspot.com/10852021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@150037 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/webkit/support/webkit_support.gypi b/webkit/support/webkit_support.gypi
index 3b46223..0630d08 100644
--- a/webkit/support/webkit_support.gypi
+++ b/webkit/support/webkit_support.gypi
@@ -71,7 +71,10 @@
         ['OS=="mac"', {
           'copies': [{
             'destination': '<(SHARED_INTERMEDIATE_DIR)/webkit',
-            'files': ['../tools/test_shell/resources/textAreaResizeCorner.png'],
+            'files': [
+              '../tools/test_shell/resources/missingImage.png',
+              '../tools/test_shell/resources/textAreaResizeCorner.png',
+            ],
           }],
         },{ # OS!="mac"
           'copies': [{