Suppress bind-framebuffer-flush-bug.html for WebGL2 on Linux AMD R7 240.

Tbr: shrekshao@google.com
No-Try: True
Bug: 1018028
Change-Id: I5e3cbca86405981ca8a41576c4b27ee11626e18e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2208537Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#770105}

content/test/gpu/gpu_tests/test_expectations/webgl2_conformance_expectations.txt

@@ -725,6 +725,7 @@ crbug.com/809595 [ no-angle linux amd ] conformance2/uniforms/simple-buffer-chan
 crbug.com/696345 [ no-angle linux amd-0x6613 ] conformance2/transform_feedback/switching-objects.html [ Failure ]
 crbug.com/913301 [ linux amd-0x6613 ] conformance2/textures/misc/generate-mipmap-with-large-base-level.html [ Failure ]
 crbug.com/809237 [ linux amd-0x6613 ] conformance2/uniforms/incompatible-texture-type-for-sampler.html [ Skip ]
+crbug.com/1018028 [ linux amd-0x6613 ] conformance/rendering/bind-framebuffer-flush-bug.html [ Failure ]
 
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 # Android failures #