Revert of Fix blits from multisampled renderbuffers to alpha:false WebGL back buffer.

content/test/gpu/gpu_tests/webgl2_conformance_expectations.py

Index: content/test/gpu/gpu_tests/webgl2_conformance_expectations.py
diff --git a/content/test/gpu/gpu_tests/webgl2_conformance_expectations.py b/content/test/gpu/gpu_tests/webgl2_conformance_expectations.py
index ef2850fcd27f8766f6782c827aa282f6b21e65f1..3d80440a91245bbca783f378824a240a3569f3d9 100644
--- a/content/test/gpu/gpu_tests/webgl2_conformance_expectations.py
+++ b/content/test/gpu/gpu_tests/webgl2_conformance_expectations.py
@@ -220,6 +220,9 @@
     # Fails on all GPU types.
     self.Fail('conformance2/glsl3/vector-dynamic-indexing-swizzled-lvalue.html',
               ['mac'], bug=709351)
+    self.Fail('conformance2/rendering/' +
+        'blitframebuffer-resolve-to-back-buffer.html',
+        ['mac'], bug=699566)
     self.Fail('conformance2/rendering/' +
         'framebuffer-completeness-unaffected.html',
         ['mac'], bug=630800)