Even more win64 warning fixes

tests/PackBitsTest.cpp

Index: tests/PackBitsTest.cpp
diff --git a/tests/PackBitsTest.cpp b/tests/PackBitsTest.cpp
index 2af4f1867daf49d40c54ea7a0e8a72354dab0f77..47a73babc601282bb140e72171f2bf42f45a9ee6 100644
--- a/tests/PackBitsTest.cpp
+++ b/tests/PackBitsTest.cpp
@@ -43,7 +43,7 @@ static void test_pack16(skiatest::Reporter* reporter) {
     }
 
     for (int n = 1000; n; n--) {
-        size_t size = 50;
+        int size = 50;
         uint16_t src[100], src2[100];
         uint8_t dst[200];
         rand_fill(src, size);
@@ -96,7 +96,7 @@ static void test_pack8(skiatest::Reporter* reporter) {
         REPORTER_ASSERT(reporter, match);
     }
 
-    for (size_t size = 1; size <= 512; size += 1) {
+    for (int size = 1; size <= 512; size += 1) {
         for (int n = 100; n; n--) {
             uint8_t src[600], src2[600];
             uint8_t dst[600];