Move sync code to include/, switch from using platform define to a proxy header in core/

src/ports/SkAtomics_win.h

-/*
- * Copyright 2013 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkAtomics_win_DEFINED
-#define SkAtomics_win_DEFINED
-
-/** Windows Interlocked atomics. */
-
-#include <intrin.h>
-#include <stdint.h>
-
-//MSDN says in order to declare an interlocked function for use as an
-//intrinsic, include intrin.h and put the function in a #pragma intrinsic
-//directive.
-//The pragma appears to be unnecessary, but doesn't hurt.
-#pragma intrinsic(_InterlockedIncrement, _InterlockedExchangeAdd, _InterlockedDecrement)
-#pragma intrinsic(_InterlockedCompareExchange)
-
-static inline int32_t sk_atomic_inc(int32_t* addr) {
-    // InterlockedIncrement returns the new value, we want to return the old.
-    return _InterlockedIncrement(reinterpret_cast<long*>(addr)) - 1;
-}
-
-static inline int64_t sk_atomic_inc(int64_t* addr) {
-    // InterlockedIncrement returns the new value, we want to return the old.
-    return InterlockedIncrement64(addr) - 1;
-}
-
-static inline int32_t sk_atomic_add(int32_t* addr, int32_t inc) {
-    return _InterlockedExchangeAdd(reinterpret_cast<long*>(addr), static_cast<long>(inc));
-}
-
-static inline int32_t sk_atomic_dec(int32_t* addr) {
-    // InterlockedDecrement returns the new value, we want to return the old.
-    return _InterlockedDecrement(reinterpret_cast<long*>(addr)) + 1;
-}
-
-static inline void sk_membar_acquire__after_atomic_dec() { }
-
-static inline bool sk_atomic_cas(int32_t* addr, int32_t before, int32_t after) {
-    return _InterlockedCompareExchange(reinterpret_cast<long*>(addr), after, before) == before;
-}
-
-static inline void* sk_atomic_cas(void** addr, void* before, void* after) {
-    return InterlockedCompareExchangePointer(addr, after, before);
-}
-
-static inline void sk_membar_acquire__after_atomic_conditional_inc() { }
-
-#endif