Enable mmap and identity-based validation caching on pnacl-{llc,ld}.nexe

ppapi/native_client/src/trusted/plugin/service_runtime.cc

Index: ppapi/native_client/src/trusted/plugin/service_runtime.cc
diff --git a/ppapi/native_client/src/trusted/plugin/service_runtime.cc b/ppapi/native_client/src/trusted/plugin/service_runtime.cc
index 9df10ed2810dbe79ea859de312a507ba5c36307e..07730da940f5d2fa3724d8cadeaafb40181d7182 100644
--- a/ppapi/native_client/src/trusted/plugin/service_runtime.cc
+++ b/ppapi/native_client/src/trusted/plugin/service_runtime.cc
@@ -251,10 +251,16 @@ void PluginReverseInterface::OpenManifestEntry_MainThreadContinuation(
 
   if (PnaclUrls::IsPnaclComponent(mapped_url)) {
     // Special PNaCl support files, that are installed on the
-    // user machine.
+    // user machine. This is usually for libraries, so they are not
+    // executable and don't interact w/ mmap'ing and validation caching.
+    uint64_t file_token_lo;
+    uint64_t file_token_hi;
     int32_t fd = PnaclResources::GetPnaclFD(
         plugin_,
-        PnaclUrls::PnaclComponentURLToFilename(mapped_url).c_str());
+        PnaclUrls::PnaclComponentURLToFilename(mapped_url).c_str(),
+        false /* is_executable */,
+        &file_token_lo,
+        &file_token_hi);
     if (fd < 0) {
       // We checked earlier if the pnacl component wasn't installed
       // yet, so this shouldn't happen. At this point, we can't do much
@@ -265,8 +271,6 @@ void PluginReverseInterface::OpenManifestEntry_MainThreadContinuation(
     }
     nacl::MutexLocker take(&mu_);
     *p->op_complete_ptr = true;  // done!
-    // TODO(ncbray): enable the fast loading and validation paths for this
-    // type of file.
     p->file_info->desc = fd;
     NaClXCondVarBroadcast(&cv_);
     NaClLog(4,