store SkAlphaType inside SkBitmap, on road to support unpremul

src/gpu/SkGpuDevice.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 "SkGpuDevice.h"
 
 #include "effects/GrTextureDomainEffect.h"
@@ skipping 120 matching lines @@
             // a 8888 is opaque based on the config.
             *isOpaque = false;
             return SkBitmap::kARGB_8888_Config;
         default:
             *isOpaque = false;
             return SkBitmap::kNo_Config;
     }
 }
 
 static SkBitmap make_bitmap(GrContext* context, GrRenderTarget* renderTarget) {
-    GrPixelConfig config = renderTarget->config();
+    bool isOpaque;
+    SkBitmap::Config config = grConfig2skConfig(renderTarget->config(), &isOpaque);
 
-    bool isOpaque;
     SkBitmap bitmap;
-    bitmap.setConfig(grConfig2skConfig(config, &isOpaque),
-                     renderTarget->width(), renderTarget->height());
-    bitmap.setIsOpaque(isOpaque);
+    bitmap.setConfig(config, renderTarget->width(), renderTarget->height(), 0,
+                     isOpaque ? kOpaque_SkAlphaType : kPremul_SkAlphaType);
     return bitmap;
 }
 
 SkGpuDevice* SkGpuDevice::Create(GrSurface* surface) {
     SkASSERT(NULL != surface);
     if (NULL == surface->asRenderTarget() || NULL == surface->getContext()) {
         return NULL;
     }
     if (surface->asTexture()) {
         return SkNEW_ARGS(SkGpuDevice, (surface->getContext(), surface->asTexture()));
@@ skipping 1720 matching lines @@
                          GrTexture* texture,
                          bool needClear)
     : SkBitmapDevice(make_bitmap(context, texture->asRenderTarget())) {
 
     SkASSERT(texture && texture->asRenderTarget());
     // This constructor is called from onCreateCompatibleDevice. It has locked the RT in the texture
     // cache. We pass true for the third argument so that it will get unlocked.
     this->initFromRenderTarget(context, texture->asRenderTarget(), true);
     fNeedClear = needClear;
 }