Fix a warning.

git-svn-id: http://skia.googlecode.com/svn/trunk@11462 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/bench/SkipZeroesBench.cpp b/bench/SkipZeroesBench.cpp
index 6e4b54b..b56838c 100644
--- a/bench/SkipZeroesBench.cpp
+++ b/bench/SkipZeroesBench.cpp
@@ -64,6 +64,12 @@
                     // Disabling until the feature is checked in.
                     // See https://codereview.chromium.org/24269006/
                     //fDecoder->setSkipWritingZeroes(fSkipZeroes);
+                    if (fSkipZeroes) {
+                        // This printf will never happen since this bench is
+                        // only currently created with false. Remove once
+                        // the above code is uncommented.
+                        SkDebugf("Should be skipping zeroes...\n");
+                    }
                 } else {
                     fValid = false;
                 }