Pure pedantry: Replace all ".size() == 0" with ".empty()".

net/tools/tld_cleanup/tld_cleanup.cc

Index: net/tools/tld_cleanup/tld_cleanup.cc
diff --git a/net/tools/tld_cleanup/tld_cleanup.cc b/net/tools/tld_cleanup/tld_cleanup.cc
index be723c45ed4b5cf0d5e8b0535b0b5671f4ecb3cb..7a8aea8f72a4bcd85811b7050ddae660765157ce 100644
--- a/net/tools/tld_cleanup/tld_cleanup.cc
+++ b/net/tools/tld_cleanup/tld_cleanup.cc
@@ -106,13 +106,13 @@ NormalizeResult NormalizeRule(std::string* domain, Rule* rule) {
   // Strip single leading and trailing dots.
   if (domain->at(0) == '.')
     domain->erase(0, 1);
-  if (domain->size() == 0) {
+  if (domain->empty()) {
     LOG(WARNING) << "Ignoring empty rule";
     return kWarning;
   }
   if (domain->at(domain->size() - 1) == '.')
     domain->erase(domain->size() - 1, 1);
-  if (domain->size() == 0) {
+  if (domain->empty()) {
     LOG(WARNING) << "Ignoring empty rule";
     return kWarning;
   }
@@ -126,7 +126,7 @@ NormalizeResult NormalizeRule(std::string* domain, Rule* rule) {
     domain->erase(0, 2);
     rule->wildcard = true;
   }
-  if (domain->size() == 0) {
+  if (domain->empty()) {
     LOG(WARNING) << "Ignoring empty rule";
     return kWarning;
   }