SkRecord: infer return type for visit() and mutate().

src/core/SkRecordPattern.h

Index: src/core/SkRecordPattern.h
diff --git a/src/core/SkRecordPattern.h b/src/core/SkRecordPattern.h
index 9493bbfaf73a46fef6704f3352d1dd9dfdebc540..45f45724c199596972772cf1b4f3df71ef212693 100644
--- a/src/core/SkRecordPattern.h
+++ b/src/core/SkRecordPattern.h
@@ -147,7 +147,7 @@ private:
     template <typename T>
     int matchFirst(T* first, SkRecord* record, int i) {
         if (i < record->count()) {
-            if (record->mutate<bool>(i, *first)) {
+            if (record->mutate(i, *first)) {
                 return i+1;
             }
         }
@@ -158,7 +158,7 @@ private:
     template <typename T>
     int matchFirst(Greedy<T>* first, SkRecord* record, int i) {
         while (i < record->count()) {
-            if (!record->mutate<bool>(i, *first)) {
+            if (!record->mutate(i, *first)) {
                 return i;
             }
             i++;