Split TLS implementation into its own translation unit.

src/ports/SkThread_pthread.cpp

Index: src/ports/SkThread_pthread.cpp
===================================================================
--- src/ports/SkThread_pthread.cpp	(revision 10093)
+++ src/ports/SkThread_pthread.cpp	(working copy)
@@ -6,7 +6,6 @@
  * found in the LICENSE file.
  */
 #include "SkThread.h"
-#include "SkTLS.h"
 
 #include <pthread.h>
 #include <errno.h>
@@ -196,25 +195,3 @@
 }
 
 #endif // !SK_USE_POSIX_THREADS
-
-///////////////////////////////////////////////////////////////////////////////
-
-static pthread_key_t gSkTLSKey;
-static pthread_once_t gSkTLSKey_Once = PTHREAD_ONCE_INIT;
-
-static void sk_tls_make_key() {
-    (void)pthread_key_create(&gSkTLSKey, SkTLS::Destructor);
-}
-
-void* SkTLS::PlatformGetSpecific(bool forceCreateTheSlot) {
-    // should we use forceCreateTheSlot to potentially skip calling pthread_once
-    // and just return NULL if we've never been called with
-    // forceCreateTheSlot==true ?
-
-    (void)pthread_once(&gSkTLSKey_Once, sk_tls_make_key);
-    return pthread_getspecific(gSkTLSKey);
-}
-
-void SkTLS::PlatformSetSpecific(void* ptr) {
-    (void)pthread_setspecific(gSkTLSKey, ptr);
-}