Improve Skia configuration.

skia/config/SkUserConfig.h

 /*
  * Copyright (C) 2006 The Android Open Source Project
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
@@ skipping 208 matching lines @@
 
 // The default crash macro writes to badbeef which can cause some strange
 // problems. Instead, pipe this through to the logging function as a fatal
 // assertion.
 #define SK_CRASH() SkDebugf_FileLine(__FILE__, __LINE__, true, "SK_CRASH")
 
 // Uncomment the following line to forward skia trace events to Chrome
 // tracing.
 // #define SK_USER_TRACE_INCLUDE_FILE "skia/ext/skia_trace_shim.h"
 
+#ifndef SK_ATOMICS_PLATFORM_H
+#  if defined(SK_BUILD_FOR_WIN)
+#    define SK_ATOMICS_PLATFORM_H "third_party/skia/src/ports/SkAtomics_win.h"
+#  elif defined(SK_BUILD_FOR_ANDROID_FRAMEWORK)
+#    define SK_ATOMICS_PLATFORM_H "third_party/skia/src/ports/SkAtomics_android.h"
+#  else
+#    define SK_ATOMICS_PLATFORM_H "third_party/skia/src/ports/SkAtomics_sync.h"
+#  endif
+#endif
+
+#ifndef SK_MUTEX_PLATFORM_H
+#  if defined(SK_BUILD_FOR_WIN)
+#    define SK_MUTEX_PLATFORM_H "third_party/skia/src/ports/SkMutex_win.h"
+#  else
+#    define SK_MUTEX_PLATFORM_H "third_party/skia/src/ports/SkMutex_pthread.h"
+#  endif
+#endif
+
 // ===== End Chrome-specific definitions =====
 
 #endif