size_t CCLayerTreeHost::calculateMemoryForRenderSurfaces(const LayerList& updateList) { size_t readbackBytes = 0; size_t maxBackgroundTextureBytes = 0; size_t contentsTextureBytes = 0; // Start iteration at 1 to skip the root surface as it does not have a texture cost. for (size_t i = 1; i < updateList.size(); ++i) { LayerChromium* renderSurfaceLayer = updateList[i].get(); RenderSurfaceChromium* renderSurface = renderSurfaceLayer->renderSurface(); size_t bytes = CCTexture::memorySizeBytes(renderSurface->contentRect().size(), GraphicsContext3D::RGBA); contentsTextureBytes += bytes; if (renderSurfaceLayer->backgroundFilters().isEmpty()) continue; if (bytes > maxBackgroundTextureBytes) maxBackgroundTextureBytes = bytes; if (!readbackBytes) readbackBytes = CCTexture::memorySizeBytes(m_deviceViewportSize, GraphicsContext3D::RGBA); } return readbackBytes + maxBackgroundTextureBytes + contentsTextureBytes; }