Move GrAutoLocaleSetter to new file and fix issue with null locale

src/gpu/GrAutoLocaleSetter.h

+/*
+ * Copyright 2015 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrAutoLocaleSetter_DEFINED
+#define GrAutoLocaleSetter_DEFINED
+
+#include "GrTypes.h"
+
+#if !defined(SK_BUILD_FOR_ANDROID)
+#include <locale.h>
+#endif
+
+#if defined(SK_BUILD_FOR_MAC) || defined(SK_BUILD_FOR_IOS)
+#include <xlocale.h>
+#endif
+
+/**
+ * Helper class for ensuring that we don't use the wrong locale when building shaders. Android
+ * doesn't support locale in the NDK, so this is a no-op there.
+ */
+class GrAutoLocaleSetter {
+public:
+    GrAutoLocaleSetter (const char* name) {
+#if defined(SK_BUILD_FOR_WIN)
+        fOldPerThreadLocale = _configthreadlocale(_ENABLE_PER_THREAD_LOCALE);
+        fOldLocale = setlocale(LC_ALL, name);
+#elif !defined(SK_BUILD_FOR_ANDROID)
+        fLocale = newlocale(LC_ALL, name, 0);
+        if (fLocale) {
+            fOldLocale = uselocale(fLocale);
+        }
+#else
+        (void) name; // suppress unused param warning.
+#endif
+    }
+
+    ~GrAutoLocaleSetter () {
+#if defined(SK_BUILD_FOR_WIN)
+        setlocale(LC_ALL, fOldLocale);
+        _configthreadlocale(fOldPerThreadLocale);
+#elif !defined(SK_BUILD_FOR_ANDROID)
+        if (fLocale) {
+             uselocale(fOldLocale);
+             freelocale(fLocale);
+        }
+#endif
+    }
+
+private:
+#if defined(SK_BUILD_FOR_WIN)
+    int fOldPerThreadLocale;
+    const char* fOldLocale;
+#elif !defined(SK_BUILD_FOR_ANDROID)
+    locale_t fOldLocale;
+    locale_t fLocale;
+#endif
+};
+
+#endif
+