Cache render targets that render to wrapped textures

src/gpu/GrSurface.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrSurface.h"
 #include "GrContext.h"
 #include "GrSurfacePriv.h"
 
 #include "SkBitmap.h"
 #include "SkGrPriv.h"
 #include "SkImageEncoder.h"
 #include <stdio.h>
 
 size_t GrSurface::WorseCaseSize(const GrSurfaceDesc& desc) {
     size_t size;
 
     bool isRenderTarget = SkToBool(desc.fFlags & kRenderTarget_GrSurfaceFlag);
     if (isRenderTarget) {
+        // We own one color value for texture storing the rendering result,
+        // e.g. the actual fbo texture attachment or the resolve texture.
         // We own one color value for each MSAA sample.
-        int colorValuesPerPixel = SkTMax(1, desc.fSampleCnt);
-        if (desc.fSampleCnt) {
-            // Worse case, we own the resolve buffer so that is one more sample per pixel.
-            colorValuesPerPixel += 1;
-        }
+        size_t colorValues = 1 + static_cast<size_t>(desc.fSampleCnt);
+
         SkASSERT(kUnknown_GrPixelConfig != desc.fConfig);
         SkASSERT(!GrPixelConfigIsCompressed(desc.fConfig));
         size_t colorBytes = GrBytesPerPixel(desc.fConfig);
         SkASSERT(colorBytes > 0);
-        size = colorValuesPerPixel * desc.fWidth * desc.fHeight * colorBytes;
+        size_t bytesPerColorValue = desc.fWidth * desc.fHeight * colorBytes;
+        size = colorValues * bytesPerColorValue;
+        // Render target that is a texture might have mipmaps in the
+        // rendering target texture.
+        size += bytesPerColorValue / 3;
     } else {
         if (GrPixelConfigIsCompressed(desc.fConfig)) {
             size = GrCompressedFormatDataSize(desc.fConfig, desc.fWidth, desc.fHeight);
         } else {
             size = (size_t) desc.fWidth * desc.fHeight * GrBytesPerPixel(desc.fConfig);
         }
 
         size += size/3;  // in case we have to mipmap
     }
 
@@ skipping 160 matching lines @@
 
 void GrSurface::onRelease() {
     this->invokeReleaseProc();
     this->INHERITED::onRelease();
 }
 
 void GrSurface::onAbandon() {
     this->invokeReleaseProc();
     this->INHERITED::onAbandon();
 }