Add rendertarget flag to prevent a debug assert in SampleApp.
BUG=skia:4223
Review URL: https://codereview.chromium.org/1301583006
diff --git a/src/gpu/gl/GrGLGpu.cpp b/src/gpu/gl/GrGLGpu.cpp
index 0945ed5..c88b0b2 100644
--- a/src/gpu/gl/GrGLGpu.cpp
+++ b/src/gpu/gl/GrGLGpu.cpp
@@ -478,7 +478,7 @@
GrSurfaceDesc desc;
desc.fConfig = wrapDesc.fConfig;
- desc.fFlags = kCheckAllocation_GrSurfaceFlag;
+ desc.fFlags = kCheckAllocation_GrSurfaceFlag | kRenderTarget_GrSurfaceFlag;
desc.fWidth = wrapDesc.fWidth;
desc.fHeight = wrapDesc.fHeight;
desc.fSampleCnt = SkTMin(wrapDesc.fSampleCnt, this->caps()->maxSampleCount());