Enable two webgl2 conformance tests.

BUG=617290
TEST=gpu bots
TBR=kbr@chromium.org
NOTRY=true
CQ_INCLUDE_TRYBOTS=tryserver.chromium.linux:linux_optional_gpu_tests_rel;tryserver.chromium.mac:mac_optional_gpu_tests_rel;tryserver.chromium.win:win_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2032063004
Cr-Commit-Position: refs/heads/master@{#397809}

content/test/gpu/gpu_tests/webgl2_conformance_expectations.py

@@ -39,9 +39,7 @@ class WebGL2ConformanceExpectations(WebGLConformanceExpectations):
     self.Skip('deqp/functional/gles3/fragmentoutput.html', bug=483282)
     self.Skip('deqp/functional/gles3/framebufferblit.html', bug=483282)
     self.Skip('deqp/functional/gles3/instancedrendering.html', bug=483282)
-    self.Skip('deqp/functional/gles3/lifetime.html', bug=483282)
     self.Skip('deqp/data/gles3/shaders/linkage.html', bug=601821)
-    self.Skip('deqp/functional/gles3/multisample.html', bug=483282)
     self.Skip('deqp/functional/gles3/negativebufferapi.html', bug=483282)
     self.Skip('deqp/functional/gles3/negativetextureapi.html', bug=483282)
     self.Skip('deqp/functional/gles3/negativevertexarrayapi.html', bug=483282)