PPAPI/NaCl: Make NaClIPCAdapter transfer handles more generally

gpu/gpu_ipc.gypi

Index: gpu/gpu_ipc.gypi
diff --git a/gpu/gpu_ipc.gypi b/gpu/gpu_ipc.gypi
index 33845f232f09f266eaf7453632977ae1b0038e09..f49904d9dc7f164ffa20d34fbdef61f1c9b5b3c8 100644
--- a/gpu/gpu_ipc.gypi
+++ b/gpu/gpu_ipc.gypi
@@ -16,4 +16,14 @@
     'ipc/gpu_command_buffer_traits.cc',
     'ipc/gpu_command_buffer_traits.h',
   ],
+  'conditions': [
+    # The NaCl Win64 build only needs the ParamTraits, so we exclude
+    # command_buffer_proxy.*.
+    ['nacl_target==1', {
+      'sources!': [
+        'ipc/command_buffer_proxy.h',
+        'ipc/command_buffer_proxy.cc',
+      ],
+    }],
+  ],
 }