Defer saves() until they're needed

tests/RecordTestUtils.h

 #ifndef RecordTestUtils_DEFINED
 #define RecordTestUtils_DEFINED
 
 #include "SkRecord.h"
 #include "SkRecords.h"
 
 // If the command we're reading is a U, set ptr to it, otherwise set it to NULL.
 template <typename U>
 struct ReadAs {
     ReadAs() : ptr(NULL), type(SkRecords::Type(~0)) {}
@@ skipping 10 matching lines @@
 // Assert that the ith command in record is of type T, and return it.
 template <typename T>
 static const T* assert_type(skiatest::Reporter* r, const SkRecord& record, unsigned index) {
     ReadAs<T> reader;
     record.visit<void>(index, reader);
     REPORTER_ASSERT(r, T::kType == reader.type);
     REPORTER_ASSERT(r, SkToBool(reader.ptr));
     return reader.ptr;
 }
 
+template <typename DrawT> struct MatchType {
+    template <typename T> int operator()(const T&) { return 0; }
+    int operator()(const DrawT&) { return 1; }
+};
+
+template <typename DrawT> int count_instances_of_type(const SkRecord& record) {
+    MatchType<DrawT> matcher;
+    int counter = 0;
+    for (unsigned i = 0; i < record.count(); i++) {
+        counter += record.visit<int>(i, matcher);
+    }
+    return counter;
+}
+
+template <typename DrawT> int find_first_instances_of_type(const SkRecord& record) {
+    MatchType<DrawT> matcher;
+    for (unsigned i = 0; i < record.count(); i++) {
+        if (record.visit<int>(i, matcher)) {
+            return i;
+        }
+    }
+    return -1;
+}
+
 #endif//RecordTestUtils_DEFINED