Restore L3 support on CrOS when the media permission is denied.

media/blink/webencryptedmediaclient_impl.cc

 // Copyright 2014 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 "webencryptedmediaclient_impl.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/string_util.h"
@@ skipping 122 matching lines @@
   NOTREACHED();
   return EME_FEATURE_NOT_ALLOWED;
 }
 
 static ConfigurationSupport GetSupportedConfiguration(
     const std::string& key_system,
     const blink::WebMediaKeySystemConfiguration& candidate,
     blink::WebMediaKeySystemConfiguration* accumulated_configuration,
     bool was_permission_requested,
     bool is_permission_granted) {
+  DCHECK(was_permission_requested || !is_permission_granted);
+
   // It is possible to obtain user permission unless permission was already
   // requested and denied.
   bool is_permission_possible =
       !was_permission_requested || is_permission_granted;
 
   // From https://w3c.github.io/encrypted-media/#get-supported-configuration
   // 1. Let accumulated configuration be empty. (Done by caller.)
   // 2. If candidate configuration's initDataTypes attribute is not empty, run
   //    the following steps:
   if (!candidate.initDataTypes.isEmpty()) {
@@ skipping 142 matching lines @@
     }
   }
 
   // 11. If implementation in the configuration specified by the combination of
   //     the values in accumulated configuration is not supported or not allowed
   //     in the origin, return null.
   di_requirement =
       ConvertRequirement(accumulated_configuration->distinctiveIdentifier);
   if (!IsDistinctiveIdentifierRequirementSupported(key_system, di_requirement,
                                                    is_permission_granted)) {
-    DCHECK(!was_permission_requested);  // Should have failed at step 3.
-    return CONFIGURATION_REQUIRES_PERMISSION;
+    if (was_permission_requested) {
+      // The optional permission was requested and denied.
+      // TODO(sandersd): Avoid the need for this logic - crbug.com/460616.
+      DCHECK(candidate.distinctiveIdentifier ==
+             blink::WebMediaKeySystemConfiguration::Requirement::Optional);
+      DCHECK(di_requirement == EME_FEATURE_REQUIRED);
+      DCHECK(!is_permission_granted);
+      accumulated_configuration->distinctiveIdentifier =
+          blink::WebMediaKeySystemConfiguration::Requirement::NotAllowed;
+    } else {
+      return CONFIGURATION_REQUIRES_PERMISSION;
+    }
   }
 
   ps_requirement =
       ConvertRequirement(accumulated_configuration->persistentState);
   if (!IsPersistentStateRequirementSupported(key_system, ps_requirement,
                                              is_permission_granted)) {
     DCHECK(!was_permission_requested);  // Should have failed at step 5.
     return CONFIGURATION_REQUIRES_PERMISSION;
   }
 
@@ skipping 181 matching lines @@
     return reporter;
 
   // Reporter not found, so create one.
   auto result =
       reporters_.add(uma_name, make_scoped_ptr(new Reporter(uma_name)));
   DCHECK(result.second);
   return result.first->second;
 }
 
 }  // namespace media