Add CdmKeyStatus::RELEASED to mojo

Status is needed for session removal in remote cdm.

BUG=
TEST=No check failure when remove session on chromecast.

Review-Url: https://codereview.chromium.org/2280743002
Cr-Commit-Position: refs/heads/master@{#414613}

media/mojo/common/media_type_converters.cc

@@ -317,6 +317,7 @@ ASSERT_CDM_KEY_STATUS(EXPIRED);
 ASSERT_CDM_KEY_STATUS(OUTPUT_RESTRICTED);
 ASSERT_CDM_KEY_STATUS(OUTPUT_DOWNSCALED);
 ASSERT_CDM_KEY_STATUS(KEY_STATUS_PENDING);
+ASSERT_CDM_KEY_STATUS(RELEASED);
 
 // CDM Message Type
 #define ASSERT_CDM_MESSAGE_TYPE(value)                                       \

media/mojo/interfaces/content_decryption_module.mojom

@@ -28,7 +28,8 @@ enum CdmKeyStatus {
   EXPIRED,
   OUTPUT_RESTRICTED,
   OUTPUT_DOWNSCALED,
-  KEY_STATUS_PENDING
+  KEY_STATUS_PENDING,
+  RELEASED
 };
 
 // Transport layer of media::CdmConfig (see media/base/cdm_config.h).