Move Google3-specific stack limitation logic to template classes.

include/gpu/gl/GrGLInterface.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLInterface_DEFINED
 #define GrGLInterface_DEFINED
 
@@ skipping 91 matching lines @@
  * be available based on the OpenGL's version and extension string must be
  * non-NULL or GrContext creation will fail. This can be tested with the
  * validate() method when the OpenGL context has been made current.
  */
 struct SK_API GrGLInterface : public SkRefCnt {
 private:
     // simple wrapper class that exists only to initialize a pointer to NULL
     template <typename FNPTR_TYPE> class GLPtr {
     public:
         GLPtr() : fPtr(NULL) {}
-        GLPtr operator=(FNPTR_TYPE ptr) { fPtr = ptr; return *this; }
+        GLPtr(const GLPtr&) = delete;
+        GLPtr& operator=(FNPTR_TYPE ptr) { fPtr = ptr; return *this; }
         operator FNPTR_TYPE() const { return fPtr; }
     private:
         FNPTR_TYPE fPtr;
     };
 
     // This is a temporary workaround to keep Chromium's GrGLInterface factories compiling until
     // they're updated to use the Functions struct.
     template <typename FNPTR_TYPE> class GLPtrAlias {
     public:
-        GLPtrAlias(GLPtr<FNPTR_TYPE>* base) : fBase(base) {}
+        explicit GLPtrAlias(GLPtr<FNPTR_TYPE>* base) : fBase(base) {}
+        GLPtrAlias(const GLPtrAlias&) = delete;
         void operator=(FNPTR_TYPE ptr) { *fBase = ptr; }
     private:
         GLPtr<FNPTR_TYPE>* fBase;
     };
 
     typedef SkRefCnt INHERITED;
 
 public:
     GrGLInterface();
 
@@ skipping 373 matching lines @@
 #if GR_GL_PER_GL_FUNC_CALLBACK
     GrGLInterfaceCallbackProc fCallback;
     GrGLInterfaceCallbackData fCallbackData;
 #endif
 
     // This exists for internal testing.
     virtual void abandon() const {}
 };
 
 #endif