Valgrind: Fix the gcc 4.2 mac build.

ui/base/keycodes/keyboard_code_conversion.cc

 // Copyright (c) 2011 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/base/keycodes/keyboard_code_conversion.h"
 
 #include "ui/base/events.h"
 
 namespace ui {
 
@@ skipping 39 matching lines @@
         case VKEY_RETURN:
           return 0x0A;
         // Returns 0 for all other keys to avoid inputting unexpected chars.
         default:
           return 0;
       }
     }
   }
 
   // Normal characters
-  if (key_code >= VKEY_0 && key_code <= VKEY_9)
-    return shift ? ")!@#$%^&*("[key_code - VKEY_0] : key_code;
-  else if (key_code >= VKEY_NUMPAD0 && key_code <= VKEY_NUMPAD9)
+  if (key_code >= VKEY_0 && key_code <= VKEY_9) {
+    return shift ? ")!@#$%^&*("[key_code - VKEY_0] :
+        static_cast<uint16>(key_code);
+  } else if (key_code >= VKEY_NUMPAD0 && key_code <= VKEY_NUMPAD9) {
     return key_code - VKEY_NUMPAD0 + '0';
+  }
 
   switch (key_code) {
     case VKEY_TAB:
       return '\t';
     case VKEY_RETURN:
       return '\r';
     case VKEY_MULTIPLY:
       return '*';
     case VKEY_ADD:
       return '+';
@@ skipping 26 matching lines @@
     case VKEY_OEM_6:
       return shift ? '}' : ']';
     case VKEY_OEM_7:
       return shift ? '"' : '\'';
     default:
       return 0;
   }
 }
 
 }  // namespace ui