Don't allow direct const char* trace value

Source/platform/PlatformInstrumentation.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 71 matching lines @@
 private:
     static const char CategoryName[];
 
     static PlatformInstrumentationClient* m_client;
 };
 
 #define FAST_RETURN_IF_NO_CLIENT_OR_NOT_MAIN_THREAD() if (!m_client || !isMainThread()) return;
 
 inline void PlatformInstrumentation::willDecodeImage(const String& imageType)
 {
-    TRACE_EVENT_BEGIN1(CategoryName, ImageDecodeEvent, ImageTypeArgument, TRACE_STR_COPY(imageType.ascii().data()));
+    TRACE_EVENT_BEGIN1(CategoryName, ImageDecodeEvent, ImageTypeArgument, imageType.ascii());
     FAST_RETURN_IF_NO_CLIENT_OR_NOT_MAIN_THREAD();
     m_client->willDecodeImage(imageType);
 }
 
 inline void PlatformInstrumentation::didDecodeImage()
 {
     TRACE_EVENT_END0(CategoryName, ImageDecodeEvent);
     FAST_RETURN_IF_NO_CLIENT_OR_NOT_MAIN_THREAD();
     m_client->didDecodeImage();
 }
@@ skipping 23 matching lines @@
 }
 
 inline void PlatformInstrumentation::didDecodeLazyPixelRef()
 {
     TRACE_EVENT_END0(CategoryName, DecodeLazyPixelRefEvent);
 }
 
 } // namespace WebCore
 
 #endif // PlatformInstrumentation_h