fix warnings

git-svn-id: http://skia.googlecode.com/svn/trunk@1129 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleAll.cpp b/samplecode/SampleAll.cpp
index bc24cd3..17b2829 100644
--- a/samplecode/SampleAll.cpp
+++ b/samplecode/SampleAll.cpp
@@ -437,7 +437,7 @@
 		SkRect rect = {0, 0, SkIntToScalar(40), SkIntToScalar(40) };
 		SkRect rect2 = {0, 0, SkIntToScalar(65), SkIntToScalar(20) };
 		SkScalar left = 0, top = 0, x = 0, y = 0;
-		int index;
+		size_t index;
 		
 		char ascii[] = "ascii...";
 		size_t asciiLength = sizeof(ascii) - 1;