Mark classes with final dtors as final

- -Wfinal-dtor-non-final-class warns on classes with final dtors but
  not final classes.
- Error messages are better when the class is marked final.
- Fix existing issues in code base and a follow up will remove warning
  exemption.

Bug: 999886
Test: no errors building
Change-Id: Ic31911e488e5b2d83ec960b2090dc44b8def25db
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2468960
Commit-Queue: Zentaro Kavanagh <zentaro@chromium.org>
Commit-Queue: Xiaohan Wang <xhwang@chromium.org>
Auto-Submit: Zentaro Kavanagh <zentaro@chromium.org>
Reviewed-by: Xiaohan Wang <xhwang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#816819}

media/mojo/clients/mojo_audio_decoder.h

@@ -25,7 +25,8 @@ namespace media {
 class MojoDecoderBufferWriter;
 
 // An AudioDecoder that proxies to a mojom::AudioDecoder.
-class MojoAudioDecoder : public AudioDecoder, public mojom::AudioDecoderClient {
+class MojoAudioDecoder final : public AudioDecoder,
+                               public mojom::AudioDecoderClient {
  public:
   MojoAudioDecoder(scoped_refptr<base::SingleThreadTaskRunner> task_runner,
                    mojo::PendingRemote<mojom::AudioDecoder> remote_decoder);

media/mojo/clients/mojo_cdm.h

@@ -37,9 +37,9 @@ class MojoDecryptor;
 // A ContentDecryptionModule that proxies to a mojom::ContentDecryptionModule.
 // That mojom::ContentDecryptionModule proxies back to the MojoCdm via the
 // mojom::ContentDecryptionModuleClient interface.
-class MojoCdm : public ContentDecryptionModule,
-                public CdmContext,
-                public mojom::ContentDecryptionModuleClient {
+class MojoCdm final : public ContentDecryptionModule,
+                      public CdmContext,
+                      public mojom::ContentDecryptionModuleClient {
  public:
   using MessageType = CdmMessageType;
 

media/mojo/clients/mojo_cdm_factory.h

@@ -14,7 +14,7 @@ namespace mojom {
 class InterfaceFactory;
 }
 
-class MojoCdmFactory : public CdmFactory {
+class MojoCdmFactory final : public CdmFactory {
  public:
   explicit MojoCdmFactory(media::mojom::InterfaceFactory* interface_factory);
   ~MojoCdmFactory() final;

media/mojo/clients/mojo_decoder_factory.h

@@ -15,7 +15,7 @@ namespace mojom {
 class InterfaceFactory;
 }
 
-class MojoDecoderFactory : public DecoderFactory {
+class MojoDecoderFactory final : public DecoderFactory {
  public:
   explicit MojoDecoderFactory(
       media::mojom::InterfaceFactory* interface_factory);

media/mojo/clients/mojo_decryptor.h

@@ -25,7 +25,7 @@ class MojoDecoderBufferWriter;
 // This class is single threaded. The |remote_decryptor| is connected before
 // being passed to MojoDecryptor, but it is bound to the thread MojoDecryptor
 // lives on the first time it is used in this class.
-class MojoDecryptor : public Decryptor {
+class MojoDecryptor final : public Decryptor {
  public:
   // |writer_capacity| can be used for testing. If 0, default writer capacity
   // will be used.

media/mojo/clients/mojo_media_log_service.h

@@ -14,7 +14,7 @@
 namespace media {
 
 // Implementation of a mojom::MediaLog service which wraps a media::MediaLog.
-class MojoMediaLogService : public mojom::MediaLog {
+class MojoMediaLogService final : public mojom::MediaLog {
  public:
   explicit MojoMediaLogService(media::MediaLog* media_log);
   ~MojoMediaLogService() final;

media/mojo/clients/mojo_renderer_factory.h

@@ -30,7 +30,7 @@ class MojoRenderer;
 // wrapper factories that use MRF, rather than creating derived MojoRenderer
 // types, or extending MRF. See DecryptingRendererFactory and
 // MediaPlayerRendererClientFactory for examples of small wrappers around MRF.
-class MojoRendererFactory : public RendererFactory {
+class MojoRendererFactory final : public RendererFactory {
  public:
   explicit MojoRendererFactory(
       media::mojom::InterfaceFactory* interface_factory);