EME: Do not special case an empty robustness string.

media/base/key_systems.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/base/key_systems.h"
 
 #include <stddef.h>
 
 #include "base/containers/hash_tables.h"
 #include "base/lazy_instance.h"
@@ skipping 736 matching lines @@
 
 EmeConfigRule KeySystemsImpl::GetRobustnessConfigRule(
     const std::string& key_system,
     EmeMediaType media_type,
     const std::string& requested_robustness) const {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   EmeRobustness robustness = ConvertRobustness(requested_robustness);
   if (robustness == EmeRobustness::INVALID)
     return EmeConfigRule::NOT_SUPPORTED;
-  if (robustness == EmeRobustness::EMPTY)
-    return EmeConfigRule::SUPPORTED;
 
   KeySystemInfoMap::const_iterator key_system_iter =
       concrete_key_system_map_.find(key_system);
   if (key_system_iter == concrete_key_system_map_.end()) {
     NOTREACHED();
     return EmeConfigRule::NOT_SUPPORTED;
   }
 
   EmeRobustness max_robustness = EmeRobustness::INVALID;
   switch (media_type) {
@@ skipping 11 matching lines @@
   if ((max_robustness == EmeRobustness::HW_SECURE_CRYPTO &&
        robustness == EmeRobustness::SW_SECURE_DECODE) ||
       (max_robustness == EmeRobustness::SW_SECURE_DECODE &&
        robustness == EmeRobustness::HW_SECURE_CRYPTO) ||
       robustness > max_robustness) {
     return EmeConfigRule::NOT_SUPPORTED;
   }
 
   if (key_system == kWidevineKeySystem) {
 #if defined(OS_CHROMEOS)
+    // TODO(ddorwin): Remove this once we have confirmed it is not necessary.
+    // See https://crbug.com/482277
+    if (robustness == EmeRobustness::EMPTY)
+      return EmeConfigRule::SUPPORTED;
+
     // Hardware security requires remote attestation.
     if (robustness >= EmeRobustness::HW_SECURE_CRYPTO)
       return EmeConfigRule::IDENTIFIER_REQUIRED;
 
     // For video, recommend remote attestation if HW_SECURE_ALL is available,
     // because it enables hardware accelerated decoding.
     // TODO(sandersd): Only do this when hardware accelerated decoding is
     // available for the requested codecs.
     if (media_type == EmeMediaType::VIDEO &&
         max_robustness == EmeRobustness::HW_SECURE_ALL) {
@@ skipping 130 matching lines @@
   KeySystemsImpl::GetInstance()->AddContainerMask(container, mask);
 }
 
 MEDIA_EXPORT void AddCodecMask(EmeMediaType media_type,
                                const std::string& codec,
                                uint32_t mask) {
   KeySystemsImpl::GetInstance()->AddCodecMask(media_type, codec, mask);
 }
 
 }  // namespace media