Make SkBitmap::CopyTo respect requested dst color type when bitmap is texture backed.

src/core/SkBitmap.cpp

 /*
  * Copyright 2008 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkAtomics.h"
 #include "SkBitmap.h"
 #include "SkColorPriv.h"
@@ skipping 810 matching lines @@
     }
 
     // if we have a texture, first get those pixels
     SkBitmap tmpSrc;
     const SkBitmap* src = this;
 
     if (fPixelRef) {
         SkIRect subset;
         subset.setXYWH(fPixelRefOrigin.fX, fPixelRefOrigin.fY,
                        fInfo.width(), fInfo.height());
-        if (fPixelRef->readPixels(&tmpSrc, &subset)) {
+        if (fPixelRef->readPixels(&tmpSrc, dstColorType, &subset)) {
             if (fPixelRef->info().alphaType() == kUnpremul_SkAlphaType) {
                 // FIXME: The only meaningful implementation of readPixels
                 // (GrPixelRef) assumes premultiplied pixels.
                 return false;
             }
             SkASSERT(tmpSrc.width() == this->width());
             SkASSERT(tmpSrc.height() == this->height());
 
             // did we get lucky and we can just return tmpSrc?
             if (tmpSrc.colorType() == dstColorType && nullptr == alloc) {
@@ skipping 495 matching lines @@
 ///////////////////////////////////////////////////////////////////////////////
 
 #ifdef SK_DEBUG
 void SkImageInfo::validate() const {
     SkASSERT(fWidth >= 0);
     SkASSERT(fHeight >= 0);
     SkASSERT(SkColorTypeIsValid(fColorType));
     SkASSERT(SkAlphaTypeIsValid(fAlphaType));
 }
 #endif