FBTF: Move a bunch of code to the headers and remove includes.

net/base/host_mapping_rules.cc

Index: net/base/host_mapping_rules.cc
diff --git a/net/base/host_mapping_rules.cc b/net/base/host_mapping_rules.cc
index a535d1446692b86773a68b1cfb1064a40074c901..e7d72b264876530ca7756cd1822c9e871e8b4ed6 100644
--- a/net/base/host_mapping_rules.cc
+++ b/net/base/host_mapping_rules.cc
@@ -12,8 +12,22 @@
 
 namespace net {
 
+struct HostMappingRules::MapRule {
+  MapRule() : replacement_port(-1) {}
+
+  std::string hostname_pattern;
+  std::string replacement_hostname;
+  int replacement_port;
+};
+
+struct HostMappingRules::ExclusionRule {
+  std::string hostname_pattern;
+};
+
 HostMappingRules::HostMappingRules() {}
 
+HostMappingRules::~HostMappingRules() {}
+
 bool HostMappingRules::RewriteHost(HostPortPair* host_port) const {
   // Check if the hostname was excluded.
   for (ExclusionRuleList::const_iterator it = exclusion_rules_.begin();