Update WebGL expectations

Remove NVIDIA Shield Tablet expectations,
since they also affect NVIDIA Shield TV.

Mark
conformance/textures/image_bitmap_from_video/tex-2d-rgb-rgb-unsigned_byte.html
Flaky on Nexus 5X.

BUG=701929, 716496
TBR=kbr@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;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

Review-Url: https://codereview.chromium.org/2851773002
Cr-Commit-Position: refs/heads/master@{#468047}

content/test/gpu/gpu_tests/webgl_conformance_expectations.py

@@ -623,6 +623,9 @@ class WebGLConformanceExpectations(GpuTestExpectations):
     self.Skip('conformance/glsl/misc/shader-with-non-reserved-words.html',
         ['android', ('qualcomm', 'Adreno (TM) 418'), 'no_passthrough'],
         bug=609883)
+    self.Flaky('conformance/textures/image_bitmap_from_video/' +
+        'tex-2d-rgb-rgb-unsigned_byte.html',
+        ['android', ('qualcomm', 'Adreno (TM) 418')], bug=716496)
     self.Fail('conformance/uniforms/uniform-samplers-test.html',
         ['android', ('qualcomm', 'Adreno (TM) 418'), 'no_passthrough'],
         bug=610951)
@@ -694,16 +697,6 @@ class WebGLConformanceExpectations(GpuTestExpectations):
         ['android', 'android-chromium',
          ('nvidia', 'NVIDIA Tegra')], bug=624621)
 
-    # NVIDIA Shield
-    self.Flaky('conformance/context/' +
-        'context-eviction-with-garbage-collection.html',
-        ['android', ('nvidia', 'NVIDIA Tegra')], bug=701929)
-    self.Flaky('conformance/glsl/misc/glsl-long-variable-names.html',
-        ['android', ('nvidia', 'NVIDIA Tegra')], bug=701929)
-    self.Flaky('conformance/textures/image_bitmap_from_video/' +
-        'tex-2d-rgb-rgb-unsigned_byte.html',
-        ['android', ('nvidia', 'NVIDIA Tegra')], bug=701929)
-
     ############
     # ChromeOS #
     ############