WebGL fingerprinting is not blocked

[luixxiul]

Test plan

#8964 (comment)

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Describe the issue you encountered: WebGL fingerprinting seems to be not blocked on https://jsfiddle.net/bkf50r8v/13/

• Brave Version (revision SHA): 1362dbc

• Steps to reproduce:

  1. Clear your profile
  2. Visit https://jsfiddle.net/bkf50r8v/13/
  3. Make sure shield is on and fingerprinting is protected

• Actual result:

  fingerprinting test
  got webgl fingerprint 
  ANGLE_instanced_arrays;EXT_blend_minmax;EXT_disjoint_timer_query;EXT_frag_depth;EXT_shader_texture_lod;EXT_sRGB;EXT_texture_filter_anisotropic;WEBKIT_EXT_texture_filter_anisotropic;OES_element_index_uint;OES_standard_derivatives;OES_texture_float;OES_texture_float_linear;OES_texture_half_float;OES_texture_half_float_linear;OES_vertex_array_object;WEBGL_compressed_texture_s3tc;WEBKIT_WEBGL_compressed_texture_s3tc;WEBGL_debug_renderer_info;WEBGL_debug_shaders;WEBGL_depth_texture;WEBKIT_WEBGL_depth_texture;WEBGL_draw_buffers;WEBGL_lose_context;WEBKIT_WEBGL_lose_context8
  

• Expected result: only fingerprinting test should be displayed

• Extra QA steps:
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  2.
  3.

• Any related issues:

I'm assigning @diracdeltas wondering if the regression would have something to do with her recent fix on WebGL fingerprinting protection.