Enable GLX/EGL backend switching while run HW video decode with libva.

content/common/gpu/media/gpu_video_decode_accelerator.cc

Index: content/common/gpu/media/gpu_video_decode_accelerator.cc
diff --git a/content/common/gpu/media/gpu_video_decode_accelerator.cc b/content/common/gpu/media/gpu_video_decode_accelerator.cc
index 08e23a33e310b087d8a0874c9e77b768d3bb058a..73c5378c10a5e143ef7281cf961333babc928606 100644
--- a/content/common/gpu/media/gpu_video_decode_accelerator.cc
+++ b/content/common/gpu/media/gpu_video_decode_accelerator.cc
@@ -278,6 +278,13 @@ void GpuVideoDecodeAccelerator::Initialize(
       make_context_current_,
       io_message_loop_));
 #elif defined(OS_CHROMEOS) && defined(ARCH_CPU_X86_FAMILY) && defined(USE_X11)
+#if defined(VAVDA_VATEXTURE_EGL_BACKEND)
+  video_decode_accelerator_.reset(new VaapiVideoDecodeAccelerator(
+      gfx::GLSurfaceEGL::GetHardwareDisplay(),
+      stub_->decoder()->GetGLContext()->GetHandle(),
+      this,
+      make_context_current_));
+#else
   gfx::GLContextGLX* glx_context =
       static_cast<gfx::GLContextGLX*>(stub_->decoder()->GetGLContext());
   GLXContext glx_context_handle =
@@ -285,6 +292,7 @@ void GpuVideoDecodeAccelerator::Initialize(
   video_decode_accelerator_.reset(new VaapiVideoDecodeAccelerator(
       glx_context->display(), glx_context_handle, this,
       make_context_current_));
+#endif
 #elif defined(OS_ANDROID)
   video_decode_accelerator_.reset(new AndroidVideoDecodeAccelerator(
       this,