Roll WebGL 4da7838..74a8e95

https://chromium.googlesource.com/external/khronosgroup/webgl.git/+log/4da7838..74a8e95

BUG=625363
TEST=bots
TBR=kbr@chromium.org
NOTRY=true
CQ_INCLUDE_TRYBOTS=tryserver.chromium.win:win_optional_gpu_tests_rel;tryserver.chromium.mac:mac_optional_gpu_tests_rel;tryserver.chromium.linux:linux_optional_gpu_tests_rel

Review-Url: https://codereview.chromium.org/2135793002
Cr-Commit-Position: refs/heads/master@{#404553}

DEPS

@@ -178,7 +178,7 @@ deps = {
     Var('chromium_git') + '/external/bidichecker/lib.git' + '@' + '97f2aa645b74c28c57eca56992235c79850fa9e0',
 
   'src/third_party/webgl/src':
-   Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + '4da7838a2303570d8a91bff810afd0920fd0e831',
+   Var('chromium_git') + '/external/khronosgroup/webgl.git' + '@' + '74a8e958422968916acd2b59c8f8715a260d0a74',
 
   'src/third_party/webdriver/pylib':
     Var('chromium_git') + '/external/selenium/py.git' + '@' + '5fd78261a75fe08d27ca4835fb6c5ce4b42275bd',

content/test/gpu/gpu_tests/webgl_conformance_expectations.py

@@ -536,14 +536,6 @@ class WebGLConformanceExpectations(GpuTestExpectations):
     # self.Fail('conformance/extensions/webgl-draw-buffers.html',
     #     ['linux', ('intel', 0x412), 'opengl'], bug=586536)
 
-
-    self.Skip('conformance/glsl/bugs/' +
-        'global-invariant-does-not-leak-across-shaders.html',
-        bug=625363)
-
-    # Fails on multiple platforms
-    self.Skip('deqp/data/gles2/shaders/preprocessor.html', bug=625363)
-
     # OpenGL / NVIDIA failures
     self.Fail('conformance/attribs/gl-disabled-vertex-attrib.html',
         ['win', 'linux', 'nvidia', 'opengl'], bug=1007) # angle bug ID