Chrome Version: 57.0.2957.0
OS: Linux (locally built content_shell)

What steps will reproduce the problem?
(1) ./content_shell --no-sandbox --in-process-gpu --disable-es3-apis http://webglreport.com/?v=2

What is the expected result?
WebGL2 should be unsupported.

What happens instead?
WebGL2 is supported.

Please use labels and text to provide additional information.
Loading chrome:gpu lists WebGL2 as "Disabled" but it is still possible to use WebGL2.
Removing --in-process-gpu makes --disable-es3-apis work as expected.

I also tried blacklisting WebGL2, but that also has no effect with --in-process-gpu.

I did some digging and found that ES3 APIs are disabled by setting the GpuPreferences::enable_es3_apis to false. This is handled in GpuDataManagerImplPrivate::AppendGpuCommandLine(...) but that function is called without a gpu_preferences parameter in the case of --in-process-gpu which leaves the pref in its default state, which is to enable es3 apis.

I did not find a obvious fix for this, GetGpuPreferencesFromCommandLine() seems like a good choice but it does not have access to the feature blacklist status afaict.