[webcodecs] Fix UaF in VideoFrame::CreateImageBitmap

The lifetime was reduced in commit 8d00b895,
making the use of base::Unretained() unsafe in this case.

Bug: 1142675
Change-Id: I57e16ee028c02313601b9a611e7e335dfdcb4aff
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2504592Reviewed-by: Eugene Zemtsov <eugene@chromium.org>
Commit-Queue: Dan Sanders <sandersd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#821536}

third_party/blink/renderer/modules/webcodecs/video_frame.cc

@@ -413,10 +413,13 @@ ScriptPromise VideoFrame::CreateImageBitmap(ScriptState* script_state,
       ri->GenUnverifiedSyncTokenCHROMIUM(sync_token.GetData());
 
       auto release_callback = viz::SingleReleaseCallback::Create(base::BindOnce(
-          [](gpu::SharedImageInterface* sii, gpu::Mailbox mailbox,
-             const gpu::SyncToken& sync_token,
-             bool is_lost) { sii->DestroySharedImage(sync_token, mailbox); },
-          base::Unretained(shared_image_interface), dest_holder.mailbox));
+          [](scoped_refptr<viz::RasterContextProvider> provider,
+             gpu::Mailbox mailbox, const gpu::SyncToken& sync_token,
+             bool is_lost) {
+            provider->SharedImageInterface()->DestroySharedImage(sync_token,
+                                                                 mailbox);
+          },
+          raster_context_provider, dest_holder.mailbox));
 
       const SkImageInfo sk_image_info =
           SkImageInfo::Make(codedWidth(), codedHeight(), kN32_SkColorType,