Add an IPC channel between the NaCl loader process and the renderer.

chrome/browser/nacl_host/nacl_process_host.cc

Index: chrome/browser/nacl_host/nacl_process_host.cc
===================================================================
--- chrome/browser/nacl_host/nacl_process_host.cc	(revision 133072)
+++ chrome/browser/nacl_host/nacl_process_host.cc	(working copy)
@@ -409,6 +409,7 @@
 struct NaClProcessHost::NaClInternal {
   std::vector<nacl::Handle> sockets_for_renderer;
   std::vector<nacl::Handle> sockets_for_sel_ldr;
+  std::string channel_name;

[Mark Seaborn, 2012/04/25 00:40:39]

This doesn't need to go in NaClInternal.  You can put it directly in
NaClProcessHost.

The header says:

  // Internal class that holds the nacl::Handle objecs so that
  // nacl_process_host.h doesn't include NaCl headers.  Needed since it's
  // included by src\content, which can't depend on the NaCl gyp file because it
  // depends on chrome.gyp (circular dependency).
  struct NaClInternal;

[bbudge, 2012/04/25 00:50:04]

Yes, I'll remove it from this struct.

 };
 
 // -----------------------------------------------------------------------------
@@ -516,6 +517,9 @@
     return;
   }
 
+  internal_->channel_name =
+      IPC::Channel::GenerateVerifiedChannelID(std::string());

[bbudge, 2012/04/25 00:50:04]

This bit of code doesn't seem to work, in that the named pipe (on Windows) can't
be created in nacl_listener. Experimenting, I mimicked the name that nacl_imc
uses for it's socket pairs and that worked. It's surprising that this should be
sensitive to the name string.

+
   // Rather than creating a socket pair in the renderer, and passing
   // one side through the browser to sel_ldr, socket pairs are created
   // in the browser and then passed to the renderer and sel_ldr.
@@ -959,6 +963,7 @@
   NaClBrowser* nacl_browser = NaClBrowser::GetInstance();
 
   nacl::NaClStartParams params;
+  params.channel_name = internal_->channel_name;
   params.validation_cache_key = nacl_browser->GetValidatorCacheKey();
   params.version = chrome::VersionInfo().CreateVersionString();
   params.enable_exception_handling = enable_exception_handling_;