Use ChannelMojo from the browser to NaCl loader process.

components/nacl/browser/nacl_process_host.cc

Index: components/nacl/browser/nacl_process_host.cc
diff --git a/components/nacl/browser/nacl_process_host.cc b/components/nacl/browser/nacl_process_host.cc
index 45b02d53b1c0a8b132cdab79e44dad1bb5d39868..4e57424125d45bddb61c9f61756bd715ab570c93 100644
--- a/components/nacl/browser/nacl_process_host.cc
+++ b/components/nacl/browser/nacl_process_host.cc
@@ -49,10 +49,12 @@
 #include "content/public/browser/web_contents.h"
 #include "content/public/common/child_process_host.h"
 #include "content/public/common/content_switches.h"
+#include "content/public/common/mojo_channel_switches.h"
 #include "content/public/common/process_type.h"
 #include "content/public/common/sandboxed_process_launcher_delegate.h"
 #include "ipc/ipc_channel.h"
 #include "ipc/ipc_switches.h"
+#include "mojo/edk/embedder/embedder.h"
 #include "net/socket/socket_descriptor.h"
 #include "ppapi/host/host_factory.h"
 #include "ppapi/host/ppapi_host.h"
@@ -163,11 +165,7 @@ content::ZygoteHandle g_nacl_zygote;
 class NaClSandboxedProcessLauncherDelegate
     : public content::SandboxedProcessLauncherDelegate {
  public:
-  NaClSandboxedProcessLauncherDelegate(ChildProcessHost* host)
-#if defined(OS_POSIX)
-      : ipc_fd_(host->TakeClientFileDescriptor())
-#endif
-  {}
+  NaClSandboxedProcessLauncherDelegate(ChildProcessHost* host) {}
 
   ~NaClSandboxedProcessLauncherDelegate() override {}
 
@@ -191,13 +189,8 @@ class NaClSandboxedProcessLauncherDelegate
   }
 #endif  // !defined(OS_MACOSX)
 
-  base::ScopedFD TakeIpcFd() override { return std::move(ipc_fd_); }
+  base::ScopedFD TakeIpcFd() override { return base::ScopedFD(-1); }

[Mark Seaborn, 2016/07/08 20:26:19]

Nit: I think you can use base::ScopedFD() without an argument here.

[Anand Mistry (off Chromium), 2016/07/12 07:26:23]

Although it's correct here, I've undone this change because it would be better
for me to eliminate SandboxedProcessLauncherDelegate::TakeIpcFD and
ChildProcessHost::TakeClientFileDescriptor everywhere at the same time instead
of in a piecemeal manner.

 #endif  // OS_WIN
-
- private:
-#if defined(OS_POSIX)
-  base::ScopedFD ipc_fd_;
-#endif  // OS_POSIX
 };
 
 void CloseFile(base::File file) {
@@ -307,9 +300,11 @@ NaClProcessHost::NaClProcessHost(
       process_type_(process_type),
       profile_directory_(profile_directory),
       render_view_id_(render_view_id),
+      mojo_child_token_(mojo::edk::GenerateRandomToken()),
       weak_factory_(this) {
   process_.reset(content::BrowserChildProcessHost::Create(
-      static_cast<content::ProcessType>(PROCESS_TYPE_NACL_LOADER), this));
+      static_cast<content::ProcessType>(PROCESS_TYPE_NACL_LOADER), this,
+      mojo_child_token_));
 
   // Set the display name so the user knows what plugin the process is running.
   // We aren't on the UI thread so getting the pref locale for language
@@ -577,9 +572,10 @@ void NaClProcessHost::LaunchNaClGdb() {
 }
 
 bool NaClProcessHost::LaunchSelLdr() {
-  std::string channel_id = process_->GetHost()->CreateChannel();
-  if (channel_id.empty()) {
-    SendErrorToRenderer("CreateChannel() failed");
+  std::string mojo_channel_token =
+      process_->GetHost()->CreateChannelMojo(mojo_child_token_);

[Mark Seaborn, 2016/07/08 20:26:19]

Since mojo_child_token_ isn't used after this, you could reset it to save a
little memory.

[Anand Mistry (off Chromium), 2016/07/12 07:26:23]

Done.

+  if (mojo_channel_token.empty()) {
+    SendErrorToRenderer("CreateChannelMojo() failed");
     return false;
   }
 
@@ -639,7 +635,7 @@ bool NaClProcessHost::LaunchSelLdr() {
                               (uses_nonsfi_mode_ ?
                                switches::kNaClLoaderNonSfiProcess :
                                switches::kNaClLoaderProcess));
-  cmd_line->AppendSwitchASCII(switches::kProcessChannelID, channel_id);
+  cmd_line->AppendSwitchASCII(switches::kMojoChannelToken, mojo_channel_token);
   if (NaClBrowser::GetDelegate()->DialogsAreSuppressed())
     cmd_line->AppendSwitch(switches::kNoErrorDialogs);
 
@@ -651,7 +647,7 @@ bool NaClProcessHost::LaunchSelLdr() {
 #if defined(OS_WIN)
   if (RunningOnWOW64()) {
     if (!NaClBrokerService::GetInstance()->LaunchLoader(
-            weak_factory_.GetWeakPtr(), channel_id)) {
+            weak_factory_.GetWeakPtr(), mojo_channel_token)) {
       SendErrorToRenderer("broker service did not launch process");
       return false;
     }