Reland: Tie kWebRtcH264WithOpenH264FFmpeg and kEnableWebRtcHWH264Encoding flags on Mac

content/common/gpu/media/vt_video_encode_accelerator_mac.cc

 // Copyright 2016 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 "content/common/gpu/media/vt_video_encode_accelerator_mac.h"
 
 #include <memory>
 
+#include "base/mac/mac_util.h"
 #include "base/thread_task_runner_handle.h"
 #include "media/base/mac/coremedia_glue.h"
 #include "media/base/mac/corevideo_glue.h"
 #include "media/base/mac/video_frame_mac.h"
 
 namespace content {
 
 namespace {
 
 // TODO(emircan): Check if we can find the actual system capabilities via
@@ skipping 65 matching lines @@
   DVLOG(3) << __FUNCTION__;
   DCHECK(thread_checker_.CalledOnValidThread());
 
   SupportedProfiles profiles;
   // Check if HW encoder is supported initially.
   videotoolbox_glue_ = VideoToolboxGlue::Get();
   if (!videotoolbox_glue_) {
     DLOG(ERROR) << "Failed creating VideoToolbox glue.";
     return profiles;
   }
+  if (!base::mac::IsOSMavericksOrLater()) {
+    DLOG(ERROR) << "VideoToolbox hardware encoder is supported on Mac OS 10.9 "
+                  "and later.";
+    return profiles;
+  }
   const bool rv = CreateCompressionSession(
       media::video_toolbox::DictionaryWithKeysAndValues(nullptr, nullptr, 0),
       gfx::Size(kDefaultResolutionWidth, kDefaultResolutionHeight), true);
   DestroyCompressionSession();
   if (!rv) {
     VLOG(1)
         << "Hardware encode acceleration is not available on this platform.";
     return profiles;
   }
 
@@ skipping 441 matching lines @@
          (encoder_thread_.IsRunning() &&
           encoder_thread_task_runner_->BelongsToCurrentThread()));
 
   if (compression_session_) {
     videotoolbox_glue_->VTCompressionSessionInvalidate(compression_session_);
     compression_session_.reset();
   }
 }
 
 } // namespace content