Pass around IPC::ChannelHandles instead of raw fds in the NaCl IRT.

ppapi/nacl_irt/ppapi_dispatcher.h

Index: ppapi/nacl_irt/ppapi_dispatcher.h
diff --git a/ppapi/nacl_irt/ppapi_dispatcher.h b/ppapi/nacl_irt/ppapi_dispatcher.h
index 4cb3b1138a86ed8f67226744b711537b1b8ea7ee..953db41a45055e996781ebc296e96a4148993a6e 100644
--- a/ppapi/nacl_irt/ppapi_dispatcher.h
+++ b/ppapi/nacl_irt/ppapi_dispatcher.h
@@ -14,6 +14,7 @@
 #include "base/files/file.h"
 #include "base/memory/ref_counted.h"
 #include "base/process/process_handle.h"
+#include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_listener.h"
 #include "ipc/ipc_platform_file.h"
 #include "ipc/ipc_sender.h"
@@ -50,8 +51,8 @@ class PpapiDispatcher : public proxy::PluginDispatcher::PluginDelegate,
  public:
   PpapiDispatcher(scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
                   base::WaitableEvent* shutdown_event,
-                  int browser_ipc_fd,
-                  int renderer_ipc_fd);
+                  IPC::ChannelHandle browser_ipc_handle,
+                  IPC::ChannelHandle renderer_ipc_handle);
 
   // PluginDispatcher::PluginDelegate implementation.
   base::SingleThreadTaskRunner* GetIPCTaskRunner() override;
@@ -94,7 +95,7 @@ class PpapiDispatcher : public proxy::PluginDispatcher::PluginDelegate,
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   base::WaitableEvent* shutdown_event_;
-  int renderer_ipc_fd_;
+  IPC::ChannelHandle renderer_ipc_handle_;
   std::unique_ptr<IPC::SyncChannel> channel_;
 };