[NaCl SDK] nacl_io: big refactor to return error value (errno).

native_client_sdk/src/libraries/nacl_io_test/kernel_wrap_test.cc

 /* Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include <string>
 #include <vector>
 #include "gtest/gtest.h"
 #include "nacl_io/kernel_proxy.h"
 #include "nacl_io/kernel_intercept.h"
@@ skipping 63 matching lines @@
 }
 
 class KernelWrapTest : public ::testing::Test {
  public:
   KernelWrapTest() {
     // Initializing the KernelProxy opens stdin/stdout/stderr.
     EXPECT_CALL(mock, open(_, _))
       .WillOnce(Return(0))
       .WillOnce(Return(1))
       .WillOnce(Return(2));
+    // And will call mount / and /dev.
+    EXPECT_CALL(mock, mount(_, _, _, _, _))
+      .WillOnce(Return(0))
+      .WillOnce(Return(0));
 
     ki_init(&mock);
   }
 
   ~KernelWrapTest() {
     ki_uninit();
   }
 
   KernelProxyMock mock;
 };
@@ skipping 141 matching lines @@
 
 TEST_F(KernelWrapTest, unlink) {
   EXPECT_CALL(mock, unlink(StrEq("unlink"))).Times(1);
   unlink("unlink");
 }
 
 TEST_F(KernelWrapTest, write) {
   EXPECT_CALL(mock, write(6789, NULL, 7891)).Times(1);
   write(6789, NULL, 7891);
 }