XPFactory lazily initializie in drawstate / GrPaint

include/gpu/GrContext.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrContext_DEFINED
 #define GrContext_DEFINED
 
@@ skipping 841 matching lines @@
     const Options                   fOptions;
 
     GrContext(const Options&); // init must be called after the constructor.
     bool init(GrBackend, GrBackendContext);
     void initMockContext();
     void initCommon();
 
     void setupDrawBuffer();
 
     class AutoCheckFlush;
-    /// Sets the paint and returns the target to draw into. The paint can be NULL in which case the
-    /// draw state is left unmodified.
+    // Sets the paint and returns the target to draw into.  This function is overloaded to either
+    // take a GrDrawState, GrPaint, and AutoCheckFlush, or JUST an AutoCheckFlush
     GrDrawTarget* prepareToDraw(GrDrawState* ds, const GrPaint* paint, const AutoCheckFlush*);
 
     void internalDrawPath(GrDrawTarget*,
                           GrDrawState*,
                           const SkMatrix& viewMatrix,
                           GrColor,
                           bool useAA,
                           const SkPath&,
                           const GrStrokeInfo&);
 
@@ skipping 14 matching lines @@
     /**
      *  This callback allows the resource cache to callback into the GrContext
      *  when the cache is still over budget after a purge.
      */
     static void OverBudgetCB(void* data);
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif