Allow Chromium to create an OpenGL ES3 context

Allow Chromium to create an OpenGL ES3 context

Removing the "STRICT_CONFORMANCE" restriction from Chromium.
This allows OpenGL ES3 context creation when using the flag
"--use-gl=swiftshader", which is the case when running layout
tests.
This does not allow WebGL 2 content to be used when using the
flag "--disable-gpu". This will require extra validation on the
Chromium side.

Change-Id: Ic4770c1acbc454a954e1ce813ebed9ed3aee5cd2
Reviewed-on: https://swiftshader-review.googlesource.com/11750
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>