fix (some) 64bit warnings -- size_t -> int

BUG=skia:
R=mtklein@google.com

Author: reed@google.com

Review URL: https://codereview.chromium.org/147053003

git-svn-id: http://skia.googlecode.com/svn/trunk@13178 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 29c09d1..71b81a1 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -1595,7 +1595,7 @@
         if (2 == count) {
             r.set(pts[0], pts[1]);
         } else {
-            r.set(pts, count);
+            r.set(pts, SkToInt(count));
         }
         SkRect storage;
         if (this->quickReject(paint.computeFastStrokeBounds(r, &storage))) {