Kill log spam from PlatformKeyboardEvent::getCurrentModifierState.

third_party/WebKit/Source/platform/PlatformKeyboardEvent.cpp

 /*
  * Copyright (C) 2006, 2007 Apple Inc.  All rights reserved.
  * Copyright (C) 2008, 2009 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 95 matching lines @@
     UInt32 currentModifiers = GetCurrentKeyModifiers();
     if (currentModifiers & ::shiftKey)
         modifiers |= ShiftKey;
     if (currentModifiers & ::controlKey)
         modifiers |= CtrlKey;
     if (currentModifiers & ::optionKey)
         modifiers |= AltKey;
     if (currentModifiers & ::cmdKey)
         modifiers |= MetaKey;
 #else
-    // See https://crbug.com/538289
-    NOTIMPLEMENTED();
+    // TODO(crbug.com/538289): Implement on other platforms.
+    return static_cast<Modifiers>(0);
 #endif
     return static_cast<Modifiers>(modifiers);
 }
 
 } // namespace blink