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

chrome/nacl/nacl_listener.cc

Index: chrome/nacl/nacl_listener.cc
===================================================================
--- chrome/nacl/nacl_listener.cc	(revision 136022)
+++ chrome/nacl/nacl_listener.cc	(working copy)
@@ -11,12 +11,14 @@
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/common/nacl_messages.h"
 #include "chrome/nacl/nacl_validation_db.h"
 #include "chrome/nacl/nacl_validation_query.h"
+#include "ipc/ipc_channel_handle.h"
+#include "ipc/ipc_switches.h"
 #include "ipc/ipc_sync_channel.h"
 #include "ipc/ipc_sync_message_filter.h"
-#include "ipc/ipc_switches.h"
 #include "native_client/src/trusted/service_runtime/sel_main_chrome.h"
 
 #if defined(OS_LINUX)
@@ -142,8 +144,10 @@
 NaClListener::NaClListener() : shutdown_event_(true, false),
                                io_thread_("NaCl_IOThread"),
                                main_loop_(NULL),
+                               nacl_ppapi_channel_(NULL),
                                debug_enabled_(false) {
   io_thread_.StartWithOptions(base::Thread::Options(MessageLoop::TYPE_IO, 0));
+  nacl_ipc_manager_.Init(io_thread_.message_loop_proxy());
 #if defined(OS_WIN)
   DCHECK(g_listener == NULL);
   g_listener = this;
@@ -198,6 +202,17 @@
     return;
   }
 
+  if (CommandLine::ForCurrentProcess()->HasSwitch(
+          switches::kEnableNaClIPCProxy)) {

[Mark Seaborn, 2012/05/11 22:45:30]

There are two problems with this in the nacl_helper process on Linux:
 * this doesn't link (switches::kEnableNaClIPCProxy isn't defined at link time).
 * this flag does not get passed through to the nacl_helper process, so this
returns false even if I use the string "enable-nacl-ipc-proxy" directly.

[bbudge, 2012/05/15 15:44:01]

Changed to use a bool sent from the browser.

+    // Create the server side of the channel and notify the process host so it
+    // can reply to the renderer, which will then try to connect as client.
+    IPC::ChannelHandle channel_handle =
+        IPC::Channel::GenerateVerifiedChannelID("nacl");
+    nacl_ppapi_channel_ = nacl_ipc_manager_.CreateChannel(channel_handle);
+
+    Send(new NaClProcessHostMsg_PpapiChannelCreated(channel_handle));
+  }
+
   std::vector<nacl::FileDescriptor> handles = params.handles;
 
 #if defined(OS_LINUX) || defined(OS_MACOSX)