Refactor NaClProcessHost. Reduce chances to leak the resource.

components/nacl/browser/nacl_process_host.h

Index: components/nacl/browser/nacl_process_host.h
diff --git a/components/nacl/browser/nacl_process_host.h b/components/nacl/browser/nacl_process_host.h
index e7e0135aecb8e69bd971abc727b4d78aa5f3d7e1..b244e08bc3d5511979a82471c8b39496c9cfb557 100644
--- a/components/nacl/browser/nacl_process_host.h
+++ b/components/nacl/browser/nacl_process_host.h
@@ -111,6 +111,8 @@ class NaClProcessHost : public content::BrowserChildProcessHostDelegate {
   content::BrowserPpapiHost* browser_ppapi_host() { return ppapi_host_.get(); }
 
  private:
+  class ScopedChannelHandle;
+
   void LaunchNaClGdb();
 
   // Mark the process as using a particular GDB debug stub port and notify
@@ -142,10 +144,10 @@ class NaClProcessHost : public content::BrowserChildProcessHostDelegate {
 
   // Sends the reply message to the renderer who is waiting for the plugin
   // to load. Returns true on success.
-  bool ReplyToRenderer(
-      const IPC::ChannelHandle& ppapi_channel_handle,
-      const IPC::ChannelHandle& trusted_channel_handle,
-      const IPC::ChannelHandle& manifest_service_channel_handle);
+  void ReplyToRenderer(
+      ScopedChannelHandle ppapi_channel_handle,
+      ScopedChannelHandle trusted_channel_handle,
+      ScopedChannelHandle manifest_service_channel_handle);
 
   // Sends the reply with error message to the renderer.
   void SendErrorToRenderer(const std::string& error_message);