unsigned -> int for counts and indices in picture-related code

tests/RecordTestUtils.h

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
 #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)) {}
 
     const U* ptr;
     SkRecords::Type type;
 
     void operator()(const U& r) { ptr = &r; type = U::kType; }
 
     template <typename T>
     void operator()(const T&) { type = U::kType; }
 };
 
 // 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) {
+static const T* assert_type(skiatest::Reporter* r, const SkRecord& record, int 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++) {
+    for (int 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++) {
+    for (int i = 0; i < record.count(); i++) {
         if (record.visit<int>(i, matcher)) {
             return i;
         }
     }
     return -1;
 }
 
 #endif//RecordTestUtils_DEFINED