clang/win: Fix style errors after https://codereview.chromium.org/1585193002

ui/events/keycodes/platform_key_map_win.cc

 // Copyright (c) 2016 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 "ui/events/keycodes/platform_key_map_win.h"
 
 #include <utility>
 
 #include "base/lazy_instance.h"
 #include "base/logging.h"
@@ skipping 26 matching lines @@
     // EF_COMMAND_DOWN,
     EF_ALTGR_DOWN,
     // EF_NUM_LOCK_ON,
     EF_CAPS_LOCK_ON,
     // EF_SCROLL_LOCK_ON
 };
 const int kModifierFlagsCombinations = (1 << arraysize(modifier_flags)) - 1;
 
 int GetModifierFlags(int combination) {
   int flags = EF_NONE;
-  for (int i = 0; i < arraysize(modifier_flags); ++i) {
+  for (size_t i = 0; i < arraysize(modifier_flags); ++i) {
     if (combination & (1 << i))
       flags |= modifier_flags[i];
   }
   return flags;
 }
 
 void SetModifierState(BYTE* keyboard_state, int flags) {
   // According to MSDN GetKeyState():
   // 1. If the high-order bit is 1, the key is down; otherwise, it is up.
   // 2. If the low-order bit is 1, the key is toggled. A key, such as the
@@ skipping 48 matching lines @@
     g_platform_key_map_tls_lazy = LAZY_INSTANCE_INITIALIZER;
 
 }  // anonymous namespace
 
 PlatformKeyMap::PlatformKeyMap() {}
 
 PlatformKeyMap::PlatformKeyMap(HKL layout) {
   UpdateLayout(layout);
 }
 
+PlatformKeyMap::~PlatformKeyMap() {}
+
 DomKey PlatformKeyMap::DomCodeAndFlagsToDomKey(DomCode code, int flags) const {
   const int flags_to_try[] = {
       // Trying to match Firefox's behavior and UIEvents DomKey guidelines.
       // If the combination doesn't produce a printable character, the key value
       // should be the key with no modifiers except for Shift and AltGr.
       // See https://w3c.github.io/uievents/#keys-guidelines
       flags,
       flags & (EF_SHIFT_DOWN | EF_ALTGR_DOWN | EF_CAPS_LOCK_ON),
       flags & (EF_SHIFT_DOWN | EF_CAPS_LOCK_ON),
       EF_NONE,
@@ skipping 81 matching lines @@
         }
       } else {
         // TODO(chongz): Handle rv <= -2 and rv >= 2.
       }
     }
   }
   ::SetKeyboardState(keyboard_state_to_restore);
 }
 
 }  // namespace ui