DXVA: Add --disable-low-latency-dxva to disable low latency decoding

content/common/gpu_host_messages.h

 // 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.
 
 // Multiply-included message file, hence no include guard here, but see below
 // for a much smaller-than-usual include guard section.
 
 #include "build/build_config.h"
 #include "content/common/content_export.h"
 #include "content/common/establish_channel_params.h"
@@ skipping 56 matching lines @@
   IPC_STRUCT_TRAITS_MEMBER(ui_prioritize_in_gpu_process)
   IPC_STRUCT_TRAITS_MEMBER(disable_accelerated_video_decode)
 #if defined(OS_CHROMEOS)
   IPC_STRUCT_TRAITS_MEMBER(disable_vaapi_accelerated_video_encode)
 #endif
 #if defined(ENABLE_WEBRTC)
   IPC_STRUCT_TRAITS_MEMBER(disable_web_rtc_hw_encoding)
 #endif
 #if defined(OS_WIN)
   IPC_STRUCT_TRAITS_MEMBER(enable_accelerated_vpx_decode)
+  IPC_STRUCT_TRAITS_MEMBER(enable_low_latency_dxva)
   IPC_STRUCT_TRAITS_MEMBER(enable_zero_copy_dxgi_video)
   IPC_STRUCT_TRAITS_MEMBER(enable_nv12_dxgi_video)
 #endif
   IPC_STRUCT_TRAITS_MEMBER(compile_shader_always_succeeds)
   IPC_STRUCT_TRAITS_MEMBER(disable_gl_error_limit)
   IPC_STRUCT_TRAITS_MEMBER(disable_glsl_translator)
   IPC_STRUCT_TRAITS_MEMBER(disable_gpu_driver_bug_workarounds)
   IPC_STRUCT_TRAITS_MEMBER(disable_shader_name_hashing)
   IPC_STRUCT_TRAITS_MEMBER(enable_gpu_command_logging)
   IPC_STRUCT_TRAITS_MEMBER(enable_gpu_debugging)
@@ skipping 137 matching lines @@
 IPC_MESSAGE_CONTROL1(GpuHostMsg_DidDestroyOffscreenContext, GURL /* url */)
 
 // Message from GPU to add a GPU log message to the about:gpu page.
 IPC_MESSAGE_CONTROL3(GpuHostMsg_OnLogMessage,
                      int /*severity*/,
                      std::string /* header */,
                      std::string /* message */)
 
 // Sent by the GPU process to indicate that a fields trial has been activated.
 IPC_MESSAGE_CONTROL1(GpuHostMsg_FieldTrialActivated, std::string /* name */)