media: Reenable TestPolicyCheck() on ChromeOS for Widevine

The original problem has been fixed in the latest Widevine CDM.

Bug: 847591,851027
Test: This CL enables a test
Change-Id: I3245bb98672b9ae872354d9f2ac6b419bc0b84b4
Reviewed-on: https://chromium-review.googlesource.com/1162907
Commit-Queue: Xiaohan Wang <xhwang@chromium.org>
Reviewed-by: John Rummell <jrummell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581329}

chrome/browser/media/encrypted_media_browsertest.cc

@@ -451,15 +451,6 @@ class EncryptedMediaTest
   }
 
   void TestPolicyCheck() {
-// TODO(crbug.com/847591): ChromeOS Widevine CDM does not support policy check
-// API yet. Remove this condition when the CDM is updated.
-#if defined(WIDEVINE_CDM_AVAILABLE) && defined(OS_CHROMEOS)
-    if (IsWidevine(CurrentKeySystem())) {
-      DVLOG(0) << "Skipping test due to HDCP policy check related bugs.";
-      return;
-    }
-#endif
-
     base::StringPairs query_params;
     // We do not care about playback so choose an arbitrary media file.
     query_params.emplace_back("mediaFile", "bear-a_enc-a.webm");