Revert "Re-enable some previously flaky single_process_mash_browser_tests"

This reverts commit d3b31cd0.

Reason for revert: Tests are still flaky:

https://crbug.com/884589#c40
Sample failures:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/29200
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/29201
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/29202
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/29203
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/29203
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/29208

Original change's description:
> Re-enable some previously flaky single_process_mash_browser_tests
> 
> Tests were blacklisted because of flakiness due to crbug.com/884589.  Now that it's fixed, renable these tests.
> 
> Bug: 884589
> Change-Id: Idc1b073c7a50636778231177488112f778d649b5
> Reviewed-on: https://chromium-review.googlesource.com/1246954
> Reviewed-by: Scott Violet <sky@chromium.org>
> Commit-Queue: Ryan Cui <rcui@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#594499}

TBR=sky@chromium.org,rcui@chromium.org

Change-Id: I9d2591b7f847270af395765fd0f27b4fd67c8045
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 884589
Reviewed-on: https://chromium-review.googlesource.com/1249263Reviewed-by: Marina Ciocea <marinaciocea@chromium.org>
Commit-Queue: Marina Ciocea <marinaciocea@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594673}

testing/buildbot/filters/chromeos.single_process_mash.browser_tests.filter

@@ -172,6 +172,18 @@
 # Default extension tests.
 -DefaultProfileExtensionBrowserTest.NoExtensionHosts
 
+# Encrypted media tests are flaky due to race condition. crbug.com/880584
+-ECKEncryptedMediaTest.*
+-EncryptedMediaTest.*
+-CDM_9/ECKEncryptedMediaTest.*
+-CDM_10/ECKEncryptedMediaTest.*
+-CDM_11/ECKEncryptedMediaTest.*
+-MSE_ClearKey/EncryptedMediaTest.*
+-MSE_ExternalClearKey/EncryptedMediaTest.*
+-MSE_Widevine/EncryptedMediaTest.*
+-SRC_ClearKey/EncryptedMediaTest.*
+-SRC_ExternalClearKey/EncryptedMediaTest.*
+
 # Failing on ASAN bot. crbug.com/882631
 -ExtensionWebRequestApiTest.WebRequestTypes
 
@@ -192,6 +204,12 @@
 -ManagedWithoutPermission/ManagedWithoutPermissionPlatformKeysTest.*
 -ManagedWithPermission/ManagedWithPermissionPlatformKeysTest.*
 
+# Needs video surface layer support. Should be fixed when renderers don't use
+# the window service for embedding.
+# https://crbug.com/884589 https://crbug.com/881574
+-MediaEngagementBrowserTest.*
+-MediaEngagementAutoplayBrowserTest.*
+
 # Flaky https://crbug.com/887175
 -PrerenderBrowserTest.PrerenderHTML5VideoJs