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/samplecode/SampleRotateCircles.cpp b/samplecode/SampleRotateCircles.cpp
index 1f586be..537f424 100644
--- a/samplecode/SampleRotateCircles.cpp
+++ b/samplecode/SampleRotateCircles.cpp
@@ -333,7 +333,7 @@
                                               unsigned modi) SK_OVERRIDE {
         for (size_t i = 0; i < SK_ARRAY_COUNT(fPts); ++i) {
             if (hittest(fPts[i], x, y)) {
-                return new MyClick(this, i);
+                return new MyClick(this, (int)i);
             }
         }
         return this->INHERITED::onFindClickHandler(x, y, modi);