Always use OverlayCandidateValidator when dc_layers is enabled.

content/browser/compositor/gpu_process_transport_factory.cc

 // Copyright 2014 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 "content/browser/compositor/gpu_process_transport_factory.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 260 matching lines @@
         GpuDataManagerImpl::GetInstance()->IsDriverBugWorkaroundActive(
             gpu::DISABLE_OVERLAY_CA_LAYERS);
     validator.reset(
         new display_compositor::CompositorOverlayCandidateValidatorMac(
             ca_layers_disabled));
   }
 #elif defined(OS_ANDROID)
   validator.reset(
       new display_compositor::CompositorOverlayCandidateValidatorAndroid());
 #elif defined(OS_WIN)
-  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
-  if (command_line->HasSwitch(switches::kEnableHardwareOverlays)) {
-    validator = base::MakeUnique<
-        display_compositor::CompositorOverlayCandidateValidatorWin>();
-  }
+  validator = base::MakeUnique<
+      display_compositor::CompositorOverlayCandidateValidatorWin>();
 #endif
 
   return validator;
 }
 
 static bool ShouldCreateGpuCompositorFrameSink(ui::Compositor* compositor) {
 #if defined(OS_CHROMEOS)
   // Software fallback does not happen on Chrome OS.
   return true;
 #endif
@@ skipping 225 matching lines @@
                 CreateOverlayCandidateValidator(compositor->widget()),
                 GL_TEXTURE_2D, GL_RGB,
                 display::DisplaySnapshot::PrimaryFormat(),
                 GetGpuMemoryBufferManager());
         gpu_vsync_control = gpu_output_surface.get();
         display_output_surface = std::move(gpu_output_surface);
 #endif
       } else {
         std::unique_ptr<display_compositor::CompositorOverlayCandidateValidator>
             validator;
-#if !defined(OS_MACOSX)
+#if defined(OS_WIN)
+        if (capabilities.dc_layers)
+          validator = CreateOverlayCandidateValidator(compositor->widget());
+#elif !defined(OS_MACOSX)
         // Overlays are only supported on surfaceless output surfaces on Mac.
         validator = CreateOverlayCandidateValidator(compositor->widget());
 #endif
         auto gpu_output_surface =
             base::MakeUnique<GpuBrowserCompositorOutputSurface>(
                 context_provider, vsync_callback, std::move(validator));
         gpu_vsync_control = gpu_output_surface.get();
         display_output_surface = std::move(gpu_output_surface);
       }
     }
@@ skipping 381 matching lines @@
       shared_vulkan_context_provider_ =
           cc::VulkanInProcessContextProvider::Create();
     }
 
     shared_vulkan_context_provider_initialized_ = true;
   }
   return shared_vulkan_context_provider_;
 }
 
 }  // namespace content