Wait for GPU to finish before committing first video overlay frame.

gpu/ipc/service/direct_composition_surface_win.cc

 // Copyright 2017 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 "gpu/ipc/service/direct_composition_surface_win.h"
 
 #include <d3d11_1.h>
 #include <dcomptypes.h>
 
 #include <deque>
@@ skipping 671 matching lines @@
     base::win::ScopedComPtr<ID3D11Texture2D> dest_texture;
     HRESULT hr =
         swap_chain_->GetBuffer(0, IID_PPV_ARGS(dest_texture.GetAddressOf()));
     DCHECK(SUCCEEDED(hr));
     base::win::ScopedComPtr<ID3D11Texture2D> src_texture;
     hr = swap_chain_->GetBuffer(1, IID_PPV_ARGS(src_texture.GetAddressOf()));
     DCHECK(SUCCEEDED(hr));
     base::win::ScopedComPtr<ID3D11DeviceContext> context;
     d3d11_device_->GetImmediateContext(context.GetAddressOf());
     context->CopyResource(dest_texture.Get(), src_texture.Get());
+
+    // Additionally wait for the GPU to finish executing its commands, or
+    // there still may be a black flicker when presenting expensive content
+    // (e.g. 4k video).
+    base::win::ScopedComPtr<IDXGIDevice2> dxgi_device2;
+    hr = d3d11_device_.CopyTo(dxgi_device2.GetAddressOf());
+    DCHECK(SUCCEEDED(hr));
+    base::WaitableEvent event(base::WaitableEvent::ResetPolicy::AUTOMATIC,
+                              base::WaitableEvent::InitialState::NOT_SIGNALED);
+    dxgi_device2->EnqueueSetEvent(event.handle());
+    event.Wait();
   }
 
   swap_chain_->Present(1, 0);
 
   UMA_HISTOGRAM_BOOLEAN("GPU.DirectComposition.SwapchainFormat",
                         is_yuy2_swapchain_);
   frames_since_color_space_change_++;
 
   base::win::ScopedComPtr<IDXGISwapChainMedia> swap_chain_media;
   if (SUCCEEDED(swap_chain_.CopyTo(swap_chain_media.GetAddressOf()))) {
@@ skipping 623 matching lines @@
 DirectCompositionSurfaceWin::GetWindowTaskRunnerForTesting() {
   return child_window_.GetTaskRunnerForTesting();
 }
 
 base::win::ScopedComPtr<IDXGISwapChain1>
 DirectCompositionSurfaceWin::GetLayerSwapChainForTesting(size_t index) const {
   return layer_tree_->GetLayerSwapChainForTesting(index);
 }
 
 }  // namespace gpu