WebGL CTS: add back expectations for blitframebuffer srgb

The expectations were eagerly removed because the test passed on Linux
Intel, but it still doesn't pass on Linux AMD and Linux Intel ANGLE

TBR=zmo@chromium.org
BUG=634525
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
NOTRY=true

Review-Url: https://codereview.chromium.org/2356773002
Cr-Commit-Position: refs/heads/master@{#419920}

content/test/gpu/gpu_tests/webgl2_conformance_expectations.py

@@ -508,6 +508,8 @@ class WebGL2ConformanceExpectations(WebGLConformanceExpectations):
     # Linux Intel with ANGLE only
     self.Fail('conformance2/textures/misc/copy-texture-image-luma-format.html',
         ['linux', 'intel', 'opengl'], bug=1492) # ANGLE bug id
+    self.Fail('conformance2/rendering/blitframebuffer-filter-srgb.html',
+        ['linux', 'intel', 'opengl'], bug=634525)
 
     # The Intel Mesa driver only supports sRGB encoding in ES 3.x, see
     # https://patchwork.freedesktop.org/patch/76903
@@ -598,6 +600,8 @@ class WebGL2ConformanceExpectations(WebGLConformanceExpectations):
         ['linux', 'amd'], bug=483282)
     self.Fail('conformance2/reading/read-pixels-into-pixel-pack-buffer.html',
         ['linux', 'amd'], bug=483282)
+    self.Fail('conformance2/rendering/blitframebuffer-filter-srgb.html',
+        ['linux', 'amd'], bug=634525)
     self.Fail('conformance2/renderbuffers/framebuffer-texture-layer.html',
         ['linux', 'amd'], bug=295792)
     self.Fail('conformance2/textures/misc/tex-mipmap-levels.html',