Suppress framebuffer-texture-level1.html on AMD GPU on Mac Retina

The test conformance2/rendering/framebuffer-texture-level1.html is flaky
on AMD GPUs on Mac Retina:

https://ci.chromium.org/p/chromium/builders/try/mac-angle-rel/4837
https://ci.chromium.org/p/chromium/builders/try/mac-angle-rel/4791

This CL will suppress that test while the issue is investigated.

Bug: 1044638
Change-Id: Iac30d591a1126d8cbdc373167ce3591b6279b210
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2015440
Auto-Submit: Tim Van Patten <timvp@google.com>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Yuly Novikov <ynovikov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#734657}

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

@@ -431,6 +431,8 @@ crbug.com/870856 [ mac amd no-passthrough ] conformance2/textures/misc/tex-mipma
 
 crbug.com/angleproject/3701 [ mac amd ] conformance2/textures/canvas/tex-2d-rg8-rg-unsigned_byte.html [ RetryOnFailure ]
 
+crbug.com/1044638 [ mac amd ] conformance2/rendering/framebuffer-texture-level1.html [ RetryOnFailure ]
+
 crbug.com/1027605 [ mac amd no-passthrough ] deqp/functional/gles3/transformfeedback/array_interleaved_lines.html [ Failure ]
 crbug.com/1027605 [ mac amd no-passthrough ] deqp/functional/gles3/transformfeedback/array_interleaved_points.html [ Failure ]
 crbug.com/1027605 [ mac amd no-passthrough ] deqp/functional/gles3/transformfeedback/array_interleaved_triangles.html [ Failure ]

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

@@ -304,7 +304,7 @@ crbug.com/905007 [ mac amd ] conformance/glsl/bugs/bool-type-cast-bug-int-float.
 crbug.com/642822 [ mac amd ] conformance/rendering/clipping-wide-points.html [ Failure ]
 crbug.com/929009 [ mac amd ] conformance/glsl/misc/shader-with-non-reserved-words.html [ RetryOnFailure ]
 
-# TODO(kbr): uncomment the following exepectation after test has
+# TODO(kbr): uncomment the following expectation after test has
 # been made more robust.
 # crbug.com/735483 [ mac amd release ] conformance/rendering/texture-switch-performance.html [ Failure ]