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

src/core/SkPixelRef.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmapCache.h"
 #include "SkMutex.h"
 #include "SkPixelRef.h"
@@ skipping 289 matching lines @@
 void SkPixelRef::setTemporarilyImmutable() {
     SkASSERT(fMutability != kImmutable);
     fMutability = kTemporarilyImmutable;
 }
 
 void SkPixelRef::restoreMutability() {
     SkASSERT(fMutability != kImmutable);
     fMutability = kMutable;
 }
 
-bool SkPixelRef::readPixels(SkBitmap* dst, const SkIRect* subset) {
-    return this->onReadPixels(dst, subset);
+bool SkPixelRef::readPixels(SkBitmap* dst, SkColorType ct, const SkIRect* subset) {
+    return this->onReadPixels(dst, ct, subset);
 }
 
 ///////////////////////////////////////////////////////////////////////////////////////////////////
 
-bool SkPixelRef::onReadPixels(SkBitmap* dst, const SkIRect* subset) {
+bool SkPixelRef::onReadPixels(SkBitmap* dst, SkColorType, const SkIRect* subset) {
     return false;
 }
 
 void SkPixelRef::onNotifyPixelsChanged() { }
 
 SkData* SkPixelRef::onRefEncodedData() {
     return nullptr;
 }
 
 bool SkPixelRef::onGetYUV8Planes(SkISize sizes[3], void* planes[3], size_t rowBytes[3],
@@ skipping 17 matching lines @@
     }
 
     result->fUnlockProc = unlock_legacy_result;
     result->fUnlockContext = SkRef(this);   // this is balanced in our fUnlockProc
     result->fCTable = fRec.fColorTable;
     result->fPixels = fRec.fPixels;
     result->fRowBytes = fRec.fRowBytes;
     result->fSize.set(fInfo.width(), fInfo.height());
     return true;
 }