generate test_shell.pak and hook up loading net resources from

net/base/net_util.cc

Index: net/base/net_util.cc
diff --git a/net/base/net_util.cc b/net/base/net_util.cc
index 6b24fe7359c40b01fa7ef2cebb2217b175490699..16adb8a885ce2bb50cae0cd4114c8b0daa22d2f7 100644
--- a/net/base/net_util.cc
+++ b/net/base/net_util.cc
@@ -807,15 +807,15 @@ std::string CanonicalizeHost(const std::wstring& host, bool* is_ip_address) {
 }
 
 std::string GetDirectoryListingHeader(const std::string& title) {
-#if defined(OS_WIN)
+#if defined(OS_WIN) || defined(OS_LINUX)
   static const StringPiece header(NetModule::GetResource(IDR_DIR_HEADER_HTML));
   if (header.empty()) {
     NOTREACHED() << "expected resource not found";
   }
   std::string result(header.data(), header.size());
-#elif defined(OS_POSIX)
+#elif defined(OS_MACOSX)
   // TODO(estade): Temporary hack. Remove these platform #ifdefs when we
-  // have implemented resources for non-Windows platforms.
+  // have implemented resources for OSX.
   LOG(INFO) << "FIXME: hacked resource loading";
   FilePath path;
   PathService::Get(base::DIR_EXE, &path);