fix more 64bit warnings

BUG=skia:

Review URL: https://codereview.chromium.org/147683003

git-svn-id: http://skia.googlecode.com/svn/trunk@13190 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/gm/typeface.cpp b/gm/typeface.cpp
index 9754e97..f2c56a5 100644
--- a/gm/typeface.cpp
+++ b/gm/typeface.cpp
@@ -50,7 +50,7 @@
 
         SkPaint paint;
         paint.setAntiAlias(true);
-        for (size_t i = 0; i < SK_ARRAY_COUNT(gFaces); i++) {
+        for (int i = 0; i < (int)SK_ARRAY_COUNT(gFaces); i++) {
             this->drawWithFace(text, i, y, paint, canvas);
         }
         // Now go backwards