Reland [Mojo Video Capture] Add test coverage for accelerated jpeg decoding

media/gpu/ipc/client/gpu_jpeg_decode_accelerator_host.cc

 // Copyright 2015 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 "media/gpu/ipc/client/gpu_jpeg_decode_accelerator_host.h"
 
 #include <stddef.h>
 
 #include "base/bind.h"
 #include "base/logging.h"
@@ skipping 13 matching lines @@
 // Class to receive AcceleratedJpegDecoderHostMsg_DecodeAck IPC message on IO
 // thread. This does very similar what MessageFilter usually does. It is not
 // MessageFilter because GpuChannelHost doesn't support AddFilter.
 class GpuJpegDecodeAcceleratorHost::Receiver : public IPC::Listener,
                                                public base::NonThreadSafe {
  public:
   Receiver(Client* client,
            const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner)
       : client_(client),
         io_task_runner_(io_task_runner),
-        weak_factory_for_io_(this) {
+        weak_factory_for_io_(
+            base::MakeUnique<base::WeakPtrFactory<Receiver>>(this)),
+        weak_ptr_for_io_(weak_factory_for_io_->GetWeakPtr()) {
     DCHECK(CalledOnValidThread());
   }
 
-  ~Receiver() override { DCHECK(CalledOnValidThread()); }
+  ~Receiver() override {
+    DCHECK(CalledOnValidThread());
+    // If |io_task_runner_| no longer accepts tasks, |weak_factory_for_io_|
+    // will leak. This is acceptable, because that should only happen on
+    // Browser shutdown.
+    io_task_runner_->DeleteSoon(FROM_HERE, weak_factory_for_io_.release());
+  }
 
-  void InvalidateWeakPtr(base::WaitableEvent* event) {
+  void InvalidateWeakPtrOnIOThread(base::WaitableEvent* event) {
     DCHECK(io_task_runner_->BelongsToCurrentThread());
-    weak_factory_for_io_.InvalidateWeakPtrs();
+    weak_factory_for_io_->InvalidateWeakPtrs();
     event->Signal();
   }
 
   // IPC::Listener implementation.
   void OnChannelError() override {
     DCHECK(io_task_runner_->BelongsToCurrentThread());
 
     OnDecodeAck(kInvalidBitstreamBufferId, PLATFORM_FAILURE);
   }
 
   bool OnMessageReceived(const IPC::Message& msg) override {
     DCHECK(io_task_runner_->BelongsToCurrentThread());
 
     bool handled = true;
     IPC_BEGIN_MESSAGE_MAP(GpuJpegDecodeAcceleratorHost::Receiver, msg)
       IPC_MESSAGE_HANDLER(AcceleratedJpegDecoderHostMsg_DecodeAck, OnDecodeAck)
       IPC_MESSAGE_UNHANDLED(handled = false)
     IPC_END_MESSAGE_MAP()
     DCHECK(handled);
     return handled;
   }
 
-  base::WeakPtr<IPC::Listener> AsWeakPtrForIO() {
-    return weak_factory_for_io_.GetWeakPtr();
-  }
+  base::WeakPtr<IPC::Listener> AsWeakPtrForIO() { return weak_ptr_for_io_; }
 
  private:
   void OnDecodeAck(int32_t bitstream_buffer_id, Error error) {
     DCHECK(io_task_runner_->BelongsToCurrentThread());
 
     if (!client_)
       return;
 
     if (error == JpegDecodeAccelerator::NO_ERRORS) {
       client_->VideoFrameReady(bitstream_buffer_id);
     } else {
       // Only NotifyError once.
       // Client::NotifyError() may trigger deletion of |this| (on another
       // thread), so calling it needs to be the last thing done on this stack!
       JpegDecodeAccelerator::Client* client = nullptr;
       std::swap(client, client_);
       client->NotifyError(bitstream_buffer_id, error);
     }
   }
 
   Client* client_;
 
   // GPU IO task runner.
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
 
   // Weak pointers will be invalidated on IO thread.
-  base::WeakPtrFactory<Receiver> weak_factory_for_io_;
+  std::unique_ptr<base::WeakPtrFactory<Receiver>> weak_factory_for_io_;
+  base::WeakPtr<Receiver> weak_ptr_for_io_;
 
   DISALLOW_COPY_AND_ASSIGN(Receiver);
 };
 
 GpuJpegDecodeAcceleratorHost::GpuJpegDecodeAcceleratorHost(
     scoped_refptr<gpu::GpuChannelHost> channel,
     int32_t route_id,
     const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner)
     : channel_(std::move(channel)),
       decoder_route_id_(route_id),
       io_task_runner_(io_task_runner) {
   DCHECK(channel_);
   DCHECK_NE(decoder_route_id_, MSG_ROUTING_NONE);
 }
 
 GpuJpegDecodeAcceleratorHost::~GpuJpegDecodeAcceleratorHost() {
   DCHECK(CalledOnValidThread());
   Send(new AcceleratedJpegDecoderMsg_Destroy(decoder_route_id_));
 
   if (receiver_) {
     channel_->RemoveRoute(decoder_route_id_);
 
     // Invalidate weak ptr of |receiver_|. After that, no more messages will be
     // routed to |receiver_| on IO thread.
     base::WaitableEvent event(base::WaitableEvent::ResetPolicy::AUTOMATIC,
                               base::WaitableEvent::InitialState::NOT_SIGNALED);
+    // Use of Unretained() is safe, because if the task executes, we block
+    // until it is finished by waiting on |event| below.
     bool task_expected_to_run = io_task_runner_->PostTask(
-        FROM_HERE, base::Bind(&Receiver::InvalidateWeakPtr,
+        FROM_HERE, base::Bind(&Receiver::InvalidateWeakPtrOnIOThread,
                               base::Unretained(receiver_.get()),
                               base::Unretained(&event)));
     // If the current call is happening during the browser shutdown, the
     // |io_task_runner_| may no longer be accepting tasks.
     if (task_expected_to_run)
       event.Wait();
   }
 }
 
 bool GpuJpegDecodeAcceleratorHost::Initialize(
@@ skipping 66 matching lines @@
   if (!channel_->Send(message)) {
     DLOG(ERROR) << "Send(" << message->type() << ") failed";
   }
 }
 
 base::WeakPtr<IPC::Listener> GpuJpegDecodeAcceleratorHost::GetReceiver() {
   return receiver_->AsWeakPtrForIO();
 }
 
 }  // namespace media