Clean up DirectCompositionUseNV12DecodeSwapChain feature.

Bug: 1126640, 869677
Change-Id: Ic8f8df88880febc088f0d57e94cb0eb6f3316a35
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2442890Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Commit-Queue: Caitlin Fischer <caitlinfischer@google.com>
Cr-Commit-Position: refs/heads/master@{#819931}

content/test/gpu/gpu_tests/power_measurement_integration_test.py

@@ -448,10 +448,7 @@ class PowerMeasurementIntegrationTest(gpu_integration_test.GpuIntegrationTest):
     PowerMeasurementIntegrationTest._LogResults(results_sum)
 
   def _RunTest_Video(self, test_path, params):
-    disabled_features = [
-        'D3D11VideoDecoder', 'DirectCompositionUseNV12DecodeSwapChain',
-        'DirectCompositionUnderlays'
-    ]
+    disabled_features = ['D3D11VideoDecoder']
 
     results_sum = {}
     for iteration in range(params.repeat):

testing/variations/fieldtrial_testing_config.json

@@ -2352,21 +2352,6 @@
             ]
         }
     ],
-    "DirectCompositionUseNV12DecodeSwapChain": [
-        {
-            "platforms": [
-                "windows"
-            ],
-            "experiments": [
-                {
-                    "name": "Enabled",
-                    "enable_features": [
-                        "DirectCompositionUseNV12DecodeSwapChain"
-                    ]
-                }
-            ]
-        }
-    ],
     "DisableForceDeferInChildFrames": [
         {
             "platforms": [