Fix UnindexedRulesetWriter finishing.

components/subresource_filter/core/common/unindexed_ruleset_unittest.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/subresource_filter/core/common/unindexed_ruleset.h"
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
+#include "base/numerics/safe_conversions.h"
 #include "base/strings/string_number_conversions.h"
 #include "components/subresource_filter/core/common/proto/rules.pb.h"
 #include "components/subresource_filter/core/common/url_pattern.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/protobuf/src/google/protobuf/io/zero_copy_stream.h"
 #include "third_party/protobuf/src/google/protobuf/io/zero_copy_stream_impl_lite.h"
 
 namespace subresource_filter {
 
 namespace {
@@ skipping 93 matching lines @@
                     const std::vector<proto::UrlRule>& expected_url_rules) {
   google::protobuf::io::ArrayInputStream array_input(ruleset_contents.data(),
                                                      ruleset_contents.size());
   UnindexedRulesetReader reader(&array_input);
   proto::FilteringRules chunk;
   std::vector<proto::UrlRule> read_rules;
   while (reader.ReadNextChunk(&chunk)) {
     read_rules.insert(read_rules.end(), chunk.url_rules().begin(),
                       chunk.url_rules().end());
   }
+  if (base::checked_cast<size_t>(reader.num_bytes_read()) !=
+      ruleset_contents.size()) {
+    return false;
+  }
 
   if (expected_url_rules.size() != read_rules.size())
     return false;
   for (size_t i = 0, size = read_rules.size(); i != size; ++i) {
     if (!IsEqual(expected_url_rules[i], read_rules[i]))
       return false;
   }
   return true;
 }
 
@@ skipping 54 matching lines @@
 
   {
     std::string ruleset_contents = builder.ruleset_contents();
     ASSERT_GT(ruleset_contents.size(), static_cast<size_t>(100));
     ruleset_contents.resize(100);
     EXPECT_FALSE(IsRulesetValid(ruleset_contents, builder.url_rules()));
   }
 }
 
 }  // namespace subresource_filter