remove sprintf

src/core/SkRegion.cpp

Index: src/core/SkRegion.cpp
diff --git a/src/core/SkRegion.cpp b/src/core/SkRegion.cpp
index a50425afd8e9d4f0bb2f3601db9d332e5f47a3a8..b3b1831aedcaae1a8063f73832ae51edbfd48e09 100644
--- a/src/core/SkRegion.cpp
+++ b/src/core/SkRegion.cpp
@@ -196,14 +196,15 @@ char* SkRegion::toString() {
     if (result == nullptr) {
         return nullptr;
     }
-    count = sprintf(result, "SkRegion(");
+    count = snprintf(result, max, "SkRegion(");
     iter.reset(*this);
     while (!iter.done()) {
         const SkIRect& r = iter.rect();
-        count += sprintf(result+count, "(%d,%d,%d,%d)", r.fLeft, r.fTop, r.fRight, r.fBottom);
+        count += snprintf(result+count, max - count, 
+                "(%d,%d,%d,%d)", r.fLeft, r.fTop, r.fRight, r.fBottom);
         iter.next();
     }
-    count += sprintf(result+count, ")");
+    count += snprintf(result+count, max - count, ")");
     return result;
 }
 #endif