start on apply gamma cleanup

src/image/SkSurface_Base.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 SkSurface_Base_DEFINED
 #define SkSurface_Base_DEFINED
 
@@ skipping 57 matching lines @@
      *  being shared with the cachedImage.
      */
     virtual void onCopyOnWrite(ContentChangeMode) = 0;
 
     /**
      *  Signal the surface to remind its backing store that it's mutable again.
      *  Called only when we _didn't_ copy-on-write; we assume the copies start mutable.
      */
     virtual void onRestoreBackingMutability() {}
 
+    virtual bool onBlitWithGamma(SkImage*, SkScalar gamma) { return false; }
+
     /**
      * Issue any pending surface IO to the current backend 3D API and resolve any surface MSAA.
      */
     virtual void onPrepareForExternalIO() {}
 
     inline SkCanvas* getCachedCanvas();
     inline sk_sp<SkImage> refCachedImage(SkBudgeted, ForceUnique);
 
     bool hasCachedImage() const { return fCachedImage != nullptr; }
 
@@ skipping 39 matching lines @@
     snap = this->onNewImageSnapshot(budgeted, fcm).release();
     if (kNo_ForceUnique == unique) {
         SkASSERT(!fCachedImage);
         fCachedImage = SkSafeRef(snap);
     }
     SkASSERT(!fCachedCanvas || fCachedCanvas->getSurfaceBase() == this);
     return sk_sp<SkImage>(snap);
 }
 
 #endif