Ignore custom offscreen surface unless explicitly opted in

content/renderer/renderer_blink_platform_impl.cc

Index: content/renderer/renderer_blink_platform_impl.cc
diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index 0bad0991e0c79661cb6165eb361cc90e2be494de..176a5470170c4b4f9ee2fa447196619586615afc 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -987,6 +987,9 @@ RendererBlinkPlatformImpl::createOffscreenGraphicsContext3DProvider(
   attributes.depth_size = web_attributes.supportDepth ? 24 : 0;
   attributes.stencil_size = web_attributes.supportStencil ? 8 : 0;
   attributes.samples = web_attributes.supportAntialias ? 4 : 0;
+  attributes.own_offscreen_surface =
+      web_attributes.supportAlpha || web_attributes.supportDepth ||
+      web_attributes.supportStencil || web_attributes.supportAntialias;
   attributes.sample_buffers = 0;
   attributes.bind_generates_resource = false;
   // Prefer discrete GPU for WebGL.