Remove macOS beta SDK workarounds for hardware VP9 decoding.

Now that we're building with the official SDK these aren't needed
anymore.

Bug: 1105187, 1115294
Test: Bots are okay, manually confirmed VP9 hardware decoding on Big Sur.
Change-Id: I9d190989a23266a5615cb149b4a958ad46d39611
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2545880
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Avi Drissman <avi@chromium.org>
Auto-Submit: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828573}

base/mac/sdk_forward_declarations.h

@@ -64,14 +64,4 @@
 //
 // ----------------------------------------------------------------------------
 
-#if !defined(MAC_OS_VERSION_11_0)
-#include <CoreMedia/CoreMedia.h>
-enum : CMVideoCodecType { kCMVideoCodecType_VP9 = 'vp09' };
-
-extern "C" {
-void VTRegisterSupplementalVideoDecoderIfAvailable(CMVideoCodecType codecType);
-}
-
-#endif  // MAC_OS_VERSION_11_0
-
 #endif  // BASE_MAC_SDK_FORWARD_DECLARATIONS_H_

media/gpu/mac/BUILD.gn

@@ -6,19 +6,12 @@ import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//media/gpu/args.gni")
 import("//media/media_options.gni")
-import("//tools/generate_stubs/rules.gni")
 import("//ui/gl/features.gni")
 
 assert(is_mac)
 
 import("//build/config/mac/mac_sdk.gni")
 
-generate_stubs("vt_beta_stubs") {
-  extra_header = "vt_beta_stubs_header.fragment"
-  sigs = [ "vt_beta.sig" ]
-  output_name = "vt_beta_stubs"
-}
-
 source_set("mac") {
   defines = [ "MEDIA_GPU_IMPLEMENTATION" ]
   visibility = [ "//media/gpu" ]
@@ -43,7 +36,6 @@ source_set("mac") {
     "VideoToolbox.framework",
   ]
   deps = [
-    ":vt_beta_stubs",
     "//base",
     "//components/crash/core/common:crash_key",
     "//gpu/command_buffer/service:gles2",

media/gpu/mac/vt_beta.h

-// Copyright 2020 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.
-
-#ifndef MEDIA_GPU_MAC_VT_BETA_H_
-#define MEDIA_GPU_MAC_VT_BETA_H_
-
-// Dynamic library loader.
-#include "media/gpu/mac/vt_beta_stubs.h"
-
-// CoreMedia and VideoToolbox types.
-#include "media/gpu/mac/vt_beta_stubs_header.fragment"
-
-// CoreMedia and VideoToolbox functions.
-extern "C" {
-#include "media/gpu/mac/vt_beta.sig"
-}  // extern "C"
-
-#endif  // MEDIA_GPU_MAC_VT_BETA_H_

media/gpu/mac/vt_beta.sig

-// Copyright 2020 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.
-
-// This function isn't available until we're using the macOS 11.0 SDK.
-void VTRegisterSupplementalVideoDecoderIfAvailable(CMVideoCodecType codecType);

media/gpu/mac/vt_beta_stubs_header.fragment

-// Copyright 2020 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 <CoreMedia/CoreMedia.h>

media/gpu/mac/vt_video_decode_accelerator_mac.cc

@@ -46,7 +46,6 @@
 #include "media/base/media_switches.h"
 #include "media/filters/vp9_parser.h"
 #include "media/gpu/mac/vp9_super_frame_bitstream_filter.h"
-#include "media/gpu/mac/vt_beta_stubs.h"
 #include "media/gpu/mac/vt_config_util.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gl/gl_context.h"
@@ -318,20 +317,8 @@ bool InitializeVideoToolboxInternal() {
 
   session.reset();
 
-  if (base::mac::IsAtLeastOS11()) {
-    // Until our target sdk version is 11.0 we need to dynamically link the
-    // VTRegisterSupplementalVideoDecoderIfAvailable() symbol in.
-    media_gpu_mac::StubPathMap paths;
-    paths[media_gpu_mac::kModuleVt_beta].push_back(FILE_PATH_LITERAL(
-        "/System/Library/Frameworks/VideoToolbox.framework/VideoToolbox"));
-    if (!media_gpu_mac::InitializeStubs(paths))
-      return true;  // VP9 support is optional.
-
-// __builtin_available doesn't work for 11.0 yet; https://crbug.com/1115294
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunguarded-availability-new"
+  if (__builtin_available(macOS 11.0, *)) {
     VTRegisterSupplementalVideoDecoderIfAvailable(kCMVideoCodecType_VP9);
-#pragma clang diagnostic pop
 
     // Create a VP9 decoding session.
     if (!CreateVideoToolboxSession(