Revert of Use the GrCacheable ID to eliminate the need for notifications to GrGpuGL when textures and RTs are…

src/gpu/GrCacheable.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrCacheable.h"
 
-uint64_t GrCacheable::CreateInstanceID() {
-    static int64_t gCacheableID;
-    uint64_t id;
-    do {
-        id = static_cast<uint64_t>(sk_atomic_inc(&gCacheableID) + 1);
-    } while (!id);
-    return id;
+uint32_t GrCacheable::getGenerationID() const {
+    static int32_t gPathRefGenerationID;
+    while (!fGenID) {
+        fGenID = static_cast<uint32_t>(sk_atomic_inc(&gPathRefGenerationID) + 1);
+    }
+    return fGenID;
 }