Convert readSurfacePixels to use a draw context instead of a texture

src/gpu/vk/GrVkGpu.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrVkGpu.h"
 
 #include "GrContextOptions.h"
@@ skipping 1370 matching lines @@
 
 bool GrVkGpu::onGetReadPixelsInfo(GrSurface* srcSurface, int width, int height, size_t rowBytes,
                                   GrPixelConfig readConfig, DrawPreference* drawPreference,
                                   ReadPixelTempDrawInfo* tempDrawInfo) {
     // These settings we will always want if a temp draw is performed.
     tempDrawInfo->fTempSurfaceDesc.fFlags = kRenderTarget_GrSurfaceFlag;
     tempDrawInfo->fTempSurfaceDesc.fWidth = width;
     tempDrawInfo->fTempSurfaceDesc.fHeight = height;
     tempDrawInfo->fTempSurfaceDesc.fSampleCnt = 0;
     tempDrawInfo->fTempSurfaceDesc.fOrigin = kTopLeft_GrSurfaceOrigin; // no CPU y-flip for TL.
-    tempDrawInfo->fUseExactScratch = false;
+    tempDrawInfo->fTempSurfaceFit = SkBackingFit::kApprox;
 
     // For now assume no swizzling, we may change that below.
     tempDrawInfo->fSwizzle = GrSwizzle::RGBA();
 
     // Depends on why we need/want a temp draw. Start off assuming no change, the surface we read
     // from will be srcConfig and we will read readConfig pixels from it.
     // Not that if we require a draw and return a non-renderable format for the temp surface the
     // base class will fail for us.
     tempDrawInfo->fTempSurfaceDesc.fConfig = srcSurface->config();
     tempDrawInfo->fReadConfig = readConfig;
@@ skipping 160 matching lines @@
     }
 
     // Currently it is fine for us to always pass in 1 for the clear count even if no attachment
     // uses it. In the current state, we also only use the LOAD_OP_CLEAR for the color attachment
     // which is always at the first attachment.
     fCurrentCmdBuffer->beginRenderPass(this, renderPass, 1, colorClear, *target, *pBounds, true);
     fCurrentCmdBuffer->executeCommands(this, buffer);
     fCurrentCmdBuffer->endRenderPass(this);
 }