Remove ThreadSafeSender from GpuVideoAcceleratorFactoriesImpl

This class has been mojified and the ThreadSafeSender appears
to be dead code.

Bug: 1102895
Change-Id: I2fe859b842e085e595fd82e5f0a3a80e0a2f4961
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2285007Reviewed-by: Dan Sanders <sandersd@chromium.org>
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/heads/master@{#786471}

content/renderer/media/gpu/gpu_video_accelerator_factories_impl.cc

@@ -96,8 +96,7 @@ GpuVideoAcceleratorFactoriesImpl::GpuVideoAcceleratorFactoriesImpl(
           enable_media_stream_gpu_memory_buffers),
       video_accelerator_enabled_(enable_video_accelerator),
       gpu_memory_buffer_manager_(
-          RenderThreadImpl::current()->GetGpuMemoryBufferManager()),
-      thread_safe_sender_(ChildThreadImpl::current()->thread_safe_sender()) {
+          RenderThreadImpl::current()->GetGpuMemoryBufferManager()) {
   DCHECK(main_thread_task_runner_);
   DCHECK(gpu_channel_host_);
 

content/renderer/media/gpu/gpu_video_accelerator_factories_impl.h

@@ -20,7 +20,6 @@
 #include "base/synchronization/waitable_event.h"
 #include "base/unguessable_token.h"
 #include "components/viz/common/gpu/context_lost_observer.h"
-#include "content/child/thread_safe_sender.h"
 #include "content/common/content_export.h"
 #include "media/mojo/mojom/interface_factory.mojom.h"
 #include "media/mojo/mojom/video_decoder.mojom.h"
@@ -200,8 +199,6 @@ class CONTENT_EXPORT GpuVideoAcceleratorFactoriesImpl
 
   base::Optional<media::VideoEncodeAccelerator::SupportedProfiles>
       supported_vea_profiles_ GUARDED_BY(supported_profiles_lock_);
-  // For sending requests to allocate shared memory in the Browser process.
-  scoped_refptr<ThreadSafeSender> thread_safe_sender_;
 
   DISALLOW_COPY_AND_ASSIGN(GpuVideoAcceleratorFactoriesImpl);
 };