Add UniqueID to GrDrawTargetCaps.

src/gpu/GrDrawTarget.cpp

 
 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 
@@ skipping 1129 matching lines @@
     SkASSERT(!fConfigTextureSupport[kUnknown_GrPixelConfig]);
 
     for (size_t i = 1; i < SK_ARRAY_COUNT(kConfigNames); ++i)  {
         r.appendf("%s is uploadable to a texture: %s\n",
                   kConfigNames[i],
                   gNY[fConfigTextureSupport[i]]);
     }
 
     return r;
 }
+
+uint32_t GrDrawTargetCaps::CreateUniqueID() {
+    static int32_t gUniqueID = SK_InvalidUniqueID;
+    uint32_t id;
+    do {
+        id = static_cast<uint32_t>(sk_atomic_inc(&gUniqueID) + 1);
+    } while (id == SK_InvalidUniqueID);
+    return id;
+}
+