Revert "Remove SkThread.h from public API."

include/gpu/GrBackendEffectFactory.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrBackendEffectFactory_DEFINED
 #define GrBackendEffectFactory_DEFINED
 
 #include "GrTypes.h"
 #include "SkTemplates.h"
+#include "SkThread.h"
 #include "SkTypes.h"
 
-#include "../../src/core/SkThread.h"
-
 /** Given a GrEffect of a particular type, creates the corresponding graphics-backend-specific
     effect object. Also tracks equivalence of shaders generated via a key. Each factory instance
     is assigned a generation ID at construction. The ID of the return of GrEffect::getFactory()
     is used as a type identifier. Thus a GrEffect subclass must return a singleton from
     getFactory(). GrEffect subclasses should use the derived class GrTBackendEffectFactory that is
     templated on the GrEffect subclass as their factory object. It requires that the GrEffect
     subclass has a nested class (or typedef) GLEffect which is its GL implementation and a subclass
     of GrGLEffect.
  */
 
@@ skipping 55 matching lines @@
         return static_cast<EffectKey>(id);
     }
 
     EffectKey fEffectClassID;
 
 private:
     static int32_t fCurrEffectClassID;
 };
 
 #endif