Use Offscreen Surface for Split Screen

tools/viewer/sk_app/android/RasterWindowContext_android.cpp

 
 /*
  * Copyright 2016 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "RasterWindowContext_android.h"
 
@@ skipping 49 matching lines @@
     fHeight = h;
     this->setBuffersGeometry();
 }
 
 sk_sp<SkSurface> RasterWindowContext_android::getBackbufferSurface() {
     if (nullptr == fBackbufferSurface) {
         ANativeWindow_lock(fNativeWindow, &fBuffer, &fBounds);
         const int bytePerPixel = fBuffer.format == WINDOW_FORMAT_RGB_565 ? 2 : 4;
         SkImageInfo info = SkImageInfo::Make(fWidth, fHeight,
                                              fDisplayParams.fColorType,
-                                             kOpaque_SkAlphaType,
+                                             kPremul_SkAlphaType,
                                              fDisplayParams.fColorSpace);
         fBackbufferSurface = SkSurface::MakeRasterDirect(
                 info, fBuffer.bits, fBuffer.stride * bytePerPixel, nullptr);
     }
     return fBackbufferSurface;
 }
 
 
 void RasterWindowContext_android::swapBuffers() {
     ANativeWindow_unlockAndPost(fNativeWindow);
     fBackbufferSurface.reset(nullptr);
 }
 
 }   // namespace sk_app