clang/win: Let some chromium_code targets build with -Wextra.

content/browser/gamepad/gamepad_platform_data_fetcher_win.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 "content/browser/gamepad/gamepad_platform_data_fetcher_win.h"
 
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
 #include "base/win/windows_version.h"
 #include "content/common/gamepad_hardware_buffer.h"
@@ skipping 16 matching lines @@
 static const BYTE kDeviceSubTypeGuitar = 6;
 static const BYTE kDeviceSubTypeGuitarAlternate = 7;
 static const BYTE kDeviceSubTypeDrumKit = 8;
 static const BYTE kDeviceSubTypeGuitarBass = 11;
 static const BYTE kDeviceSubTypeArcadePad = 19;
 
 float NormalizeXInputAxis(SHORT value) {
   return ((value + 32768.f) / 32767.5f) - 1.f;
 }
 
-const WebUChar* const GamepadSubTypeName(BYTE sub_type) {
+const WebUChar* GamepadSubTypeName(BYTE sub_type) {
   switch (sub_type) {
     case kDeviceSubTypeGamepad: return L"GAMEPAD";
     case kDeviceSubTypeWheel: return L"WHEEL";
     case kDeviceSubTypeArcadeStick: return L"ARCADE_STICK";
     case kDeviceSubTypeFlightStick: return L"FLIGHT_STICK";
     case kDeviceSubTypeDancePad: return L"DANCE_PAD";
     case kDeviceSubTypeGuitar: return L"GUITAR";
     case kDeviceSubTypeGuitarAlternate: return L"GUITAR_ALTERNATE";
     case kDeviceSubTypeDrumKit: return L"DRUM_KIT";
     case kDeviceSubTypeGuitarBass: return L"GUITAR_BASS";
@@ skipping 276 matching lines @@
     return false;
   xinput_get_state_ = reinterpret_cast<XInputGetStateFunc>(
       xinput_dll_.GetFunctionPointer("XInputGetState"));
   if (!xinput_get_state_)
     return false;
   xinput_enable_(true);
   return true;
 }
 
 }  // namespace content