Remove -Wno-unused-private-field clang warning suppression.

sandbox/win/src/ipc_unittest.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 "base/basictypes.h"
 #include "sandbox/win/src/crosscall_client.h"
 #include "sandbox/win/src/crosscall_server.h"
 #include "sandbox/win/src/sharedmem_ipc_client.h"
 #include "sandbox/win/src/sharedmem_ipc_server.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 374 matching lines @@
   ::InterlockedExchange(events->state, kAckChannel);
   ::SetEvent(events->pong);
   return wait_result;
 }
 
 class CrossCallParamsMock : public CrossCallParams {
  public:
   CrossCallParamsMock(uint32 tag, uint32 params_count)
       :  CrossCallParams(tag, params_count) {
   }
- private:
-  void* params[4];
 };
 
 void FakeOkAnswerInChannel(void* channel) {
   CrossCallReturn* answer = reinterpret_cast<CrossCallReturn*>(channel);
   answer->call_outcome = SBOX_ALL_OK;
 }
 
 // Create two threads that will quickly answer IPCs; the first one
 // using channel 1 (channel 0 is busy) and one using channel 0. No time-out
 // should occur.
@@ skipping 219 matching lines @@
                                                  &call_return));
   EXPECT_EQ(SBOX_ALL_OK, call_return.call_outcome);
   EXPECT_TRUE(bar == call_return.extended[0].handle);
   EXPECT_EQ(foo, call_return.extended[1].unsigned_int);
 
   CloseChannelEvents(client_control);
   delete[] reinterpret_cast<char*>(client_control);
 }
 
 }  // namespace sandbox