Cache render targets that render to wrapped textures

src/gpu/gl/GrGLTextureRenderTarget.cpp

Index: src/gpu/gl/GrGLTextureRenderTarget.cpp
diff --git a/src/gpu/gl/GrGLTextureRenderTarget.cpp b/src/gpu/gl/GrGLTextureRenderTarget.cpp
index b6068a4e56efc5b250872df3ed7931251357d034..fe4f9fced536a67d948b2b5305371122b0f39472 100644
--- a/src/gpu/gl/GrGLTextureRenderTarget.cpp
+++ b/src/gpu/gl/GrGLTextureRenderTarget.cpp
@@ -37,3 +37,10 @@ void GrGLTextureRenderTarget::dumpMemoryStatistics(
   traceMemoryDump->setMemoryBacking(dumpName.c_str(), "gl_texture",
                                     texture_id.c_str());
 }
+
+bool GrGLTextureRenderTarget::refsWrappedResources() const {
+    // The GrGLRenderTarget part of this class will not reference external resources, because client
+    // provides either an external texture or an external fbo, never both. The external texture
+    // produces GrGLTextureRenderTarget, the external fbo produces plain GrGLRenderTarget.o
+    return this->GrGLTexture::refsWrappedResources();
+}