Enable Mac-specific GPU switching tests.

The following tests are enabled:

  ContextLost_MacWebGLMultisamplingHighPowerSwitchLosesContext
  ContextLost_MacWebGLPreserveDBHighPowerSwitchLosesContext
  GpuProcess_mac_webgl_backgrounded_high_performance
  GpuProcess_mac_webgl_high_performance
  GpuProcess_mac_webgl_low_power
  GpuProcess_mac_webgl_terminated_high_performance
  Pixel_WebGLHighToLowPower
  Pixel_WebGLLowToHighPower

Bug: 681341
No-Try: True
Tbr: ccameron@chromium.org
Tbr: jdarpinian@chromium.org
Change-Id: I996cc9e195eb4d398691ee816cbf6c404be3f4c2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1906881
Commit-Queue: Kenneth Russell <kbr@chromium.org>
Reviewed-by: ccameron <ccameron@chromium.org>
Reviewed-by: James Darpinian <jdarpinian@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#713990}

content/test/gpu/gpu_tests/test_expectations/context_lost_expectations.txt

@@ -45,9 +45,3 @@ crbug.com/611906 [ android qualcomm-adreno-(tm)-420 ] ContextLost_WebGLContextLo
 crbug.com/609629 [ android qualcomm-adreno-(tm)-420 ] GpuCrash_GPUProcessCrashesExactlyOncePerVisitToAboutGpuCrash [ Skip ]
 crbug.com/609629 [ android qualcomm-adreno-(tm)-420 ] ContextLost_WebGLContextLostFromGPUProcessExit [ Skip ]
 crbug.com/609629 [ android qualcomm-adreno-(tm)-420 ] ContextLost_WebGLContextLostInHiddenTab [ Skip ]
-
-# TODO(crbug.com/681341): enable these new tests immediately after they land.
-# Disabled upon landing only to avoid having the entire CL reverted if the new
-# tests turn out to be flaky.
-crbug.com/681341 ContextLost_MacWebGLMultisamplingHighPowerSwitchLosesContext [ Skip ]
-crbug.com/681341 ContextLost_MacWebGLPreserveDBHighPowerSwitchLosesContext [ Skip ]

content/test/gpu/gpu_tests/test_expectations/gpu_process_expectations.txt

@@ -5,11 +5,3 @@ crbug.com/257109 [ linux ] GpuProcess_video [ Failure ]
 
 # Seems to have become flaky on Windows recently.
 crbug.com/700522 [ win ] GpuProcess_one_extra_workaround [ RetryOnFailure ]
-
-# TODO(crbug.com/681341): enable these new tests immediately after they land.
-# Disabled upon landing only to avoid having the entire CL reverted if the new
-# tests turn out to be flaky.
-crbug.com/681341 GpuProcess_mac_webgl_backgrounded_high_performance [ Skip ]
-crbug.com/681341 GpuProcess_mac_webgl_high_performance [ Skip ]
-crbug.com/681341 GpuProcess_mac_webgl_low_power [ Skip ]
-crbug.com/681341 GpuProcess_mac_webgl_terminated_high_performance [ Skip ]

content/test/gpu/gpu_tests/test_expectations/pixel_expectations.txt

@@ -233,9 +233,3 @@ crbug.com/1019462 [ android nvidia no-skia-renderer ] Pixel_Video_MP4_FourColors
 crbug.com/1019462 [ android nvidia no-skia-renderer ] Pixel_Video_MP4_Rounded_Corner [ RetryOnFailure ]
 crbug.com/1019462 [ android nvidia no-skia-renderer ] Pixel_Video_Context_Loss_VP9 [ RetryOnFailure ]
 crbug.com/1019462 [ android nvidia no-skia-renderer ] Pixel_WebGL2_BlitFramebuffer_Result_Displayed [ RetryOnFailure ]
-
-# TODO(crbug.com/681341): enable these new tests immediately after they land.
-# Disabled upon landing only to avoid having the entire CL reverted if the new
-# tests turn out to be flaky.
-crbug.com/681341 [ mac ] Pixel_WebGLHighToLowPower [ Skip ]
-crbug.com/681341 [ mac ] Pixel_WebGLLowToHighPower [ Skip ]