[Do not submit] D3DKMTWaitForVerticalBlankEvent VSync prototype

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"
 #include "base/command_line.h"
 #include "base/location.h"
 #include "base/memory/ptr_util.h"
+#include "base/metrics/field_trial.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/profiler/scoped_tracker.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/simple_thread.h"
 #include "base/threading/thread.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #include "cc/base/histograms.h"
 #include "cc/output/texture_mailbox_deleter.h"
 #include "cc/output/vulkan_in_process_context_provider.h"
@@ skipping 27 matching lines @@
 #include "services/service_manager/runner/common/client_util.h"
 #include "services/ui/public/cpp/gpu/context_provider_command_buffer.h"
 #include "third_party/khronos/GLES2/gl2.h"
 #include "ui/compositor/compositor.h"
 #include "ui/compositor/compositor_constants.h"
 #include "ui/compositor/compositor_switches.h"
 #include "ui/compositor/layer.h"
 #include "ui/display/types/display_snapshot.h"
 #include "ui/gfx/geometry/size.h"
 #include "ui/gfx/switches.h"
+#include "ui/gl/gl_switches.h"
 
 #if defined(USE_AURA)
 #include "content/browser/compositor/mus_browser_compositor_output_surface.h"
 #include "content/public/common/service_manager_connection.h"
 #include "ui/aura/window_tree_host.h"
 #endif
 
 #if defined(OS_WIN)
 #include "content/browser/compositor/software_output_device_win.h"
 #include "ui/gfx/win/rendering_window_manager.h"
@@ skipping 29 matching lines @@
 using gpu::gles2::GLES2Interface;
 
 namespace {
 
 const int kNumRetriesBeforeSoftwareFallback = 4;
 
 bool IsUsingMus() {
   return service_manager::ServiceManagerIsRemote();
 }
 
+bool IsGpuVSyncSignalSupported() {
+#if defined(OS_WIN)
+  base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kUseD3DVSync))
+    return true;
+
+  const std::string group_name =
+      base::FieldTrialList::FindFullName("UseD3DVSync");
+  return group_name == "Enabled";
+#else
+  return false;
+#endif  // defined(OS_WIN)
+}
+
 scoped_refptr<ui::ContextProviderCommandBuffer> CreateContextCommon(
     scoped_refptr<gpu::GpuChannelHost> gpu_channel_host,
     gpu::SurfaceHandle surface_handle,
     bool need_alpha_channel,
     bool support_locking,
     ui::ContextProviderCommandBuffer* shared_context_provider,
     ui::command_buffer_metrics::ContextType type) {
   DCHECK(
       content::GpuDataManagerImpl::GetInstance()->CanUseGpuBrowserCompositor());
   DCHECK(gpu_channel_host);
@@ skipping 320 matching lines @@
       gpu::GpuChannelEstablishedCallback callback(
           base::Bind(&GpuProcessTransportFactory::EstablishedGpuChannel,
                      callback_factory_.GetWeakPtr(), compositor,
                      create_gpu_output_surface, num_attempts + 1));
       DCHECK(gpu_channel_factory_);
       gpu_channel_factory_->EstablishGpuChannel(callback);
       return;
     }
   }
 
-  std::unique_ptr<cc::SyntheticBeginFrameSource> synthetic_begin_frame_source;
-  if (!compositor->GetRendererSettings().disable_display_vsync) {
-    synthetic_begin_frame_source.reset(new cc::DelayBasedBeginFrameSource(
-        base::MakeUnique<cc::DelayBasedTimeSource>(
-            compositor->task_runner().get())));
-  } else {
-    synthetic_begin_frame_source.reset(new cc::BackToBackBeginFrameSource(
-        base::MakeUnique<cc::DelayBasedTimeSource>(
-            compositor->task_runner().get())));
-  }
-  cc::BeginFrameSource* begin_frame_source = synthetic_begin_frame_source.get();
-
   BrowserCompositorOutputSurface::UpdateVSyncParametersCallback vsync_callback =
       base::Bind(&ui::Compositor::SetDisplayVSyncParameters, compositor);
+  cc::BeginFrameSource* begin_frame_source = nullptr;
 
   std::unique_ptr<BrowserCompositorOutputSurface> display_output_surface;
 #if defined(ENABLE_VULKAN)
   std::unique_ptr<VulkanBrowserCompositorOutputSurface> vulkan_surface;
   if (vulkan_context_provider) {
     vulkan_surface.reset(new VulkanBrowserCompositorOutputSurface(
         vulkan_context_provider, vsync_callback));
     if (!vulkan_surface->Initialize(compositor.get()->widget())) {
       vulkan_surface->Destroy();
       vulkan_surface.reset();
@@ skipping 40 matching lines @@
         const bool use_mus = IsUsingMus();
 #if !defined(OS_MACOSX)
         // Overlays are only supported on surfaceless output surfaces on Mac.
         if (!use_mus)
           validator = CreateOverlayCandidateValidator(compositor->widget());
 #endif
         if (!use_mus) {
           display_output_surface =
               base::MakeUnique<GpuBrowserCompositorOutputSurface>(
                   context_provider, vsync_callback, std::move(validator));
+
         } else {
 #if defined(USE_AURA)
           std::unique_ptr<MusBrowserCompositorOutputSurface> mus_output_surface;
           if (compositor->window()) {
             // TODO(mfomitchev): Remove this clause once we complete the switch
             // to Aura-Mus.
             mus_output_surface =
                 base::MakeUnique<MusBrowserCompositorOutputSurface>(
                     compositor->window(), context_provider,
                     GetGpuMemoryBufferManager(), vsync_callback,
                     std::move(validator));
           } else {
             aura::WindowTreeHost* host =
                 aura::WindowTreeHost::GetForAcceleratedWidget(
                     compositor->widget());
             mus_output_surface =
                 base::MakeUnique<MusBrowserCompositorOutputSurface>(
                     host->window(), context_provider,
                     GetGpuMemoryBufferManager(), vsync_callback,
                     std::move(validator));
           }
           // We use the ExternalBeginFrameSource provided by the output surface
           // instead of our own synthetic one.
-          synthetic_begin_frame_source.reset();
           begin_frame_source = mus_output_surface->GetBeginFrameSource();
           DCHECK(begin_frame_source);
           display_output_surface = std::move(mus_output_surface);
 #else
           NOTREACHED();
 #endif
         }
       }
     }
   }
 
-  data->display_output_surface = display_output_surface.get();
+  std::unique_ptr<cc::SyntheticBeginFrameSource> synthetic_begin_frame_source;
+
+  if (!begin_frame_source) {
+    if (!compositor->GetRendererSettings().disable_display_vsync) {
+      GpuVSyncControl* vsync_control =
+          display_output_surface->GetVSyncControl();
+      if (vsync_control && IsGpuVSyncSignalSupported()) {
+        synthetic_begin_frame_source.reset(
+            new GpuVSyncBeginFrameSource(vsync_control));
+      } else {
+        synthetic_begin_frame_source.reset(new cc::DelayBasedBeginFrameSource(
+            base::MakeUnique<cc::DelayBasedTimeSource>(
+                compositor->task_runner().get())));
+      }
+    } else {
+      synthetic_begin_frame_source.reset(new cc::BackToBackBeginFrameSource(
+          base::MakeUnique<cc::DelayBasedTimeSource>(
+              compositor->task_runner().get())));
+    }
+
+    begin_frame_source = synthetic_begin_frame_source.get();
+  }
+
   if (data->reflector)
     data->reflector->OnSourceSurfaceReady(data->display_output_surface);
 
 #if defined(OS_WIN)
   gfx::RenderingWindowManager::GetInstance()->DoSetParentOnChild(
       compositor->widget());
 #endif
 
   std::unique_ptr<cc::DisplayScheduler> scheduler(new cc::DisplayScheduler(
       compositor->task_runner().get(),
@@ skipping 337 matching lines @@
       shared_vulkan_context_provider_ =
           cc::VulkanInProcessContextProvider::Create();
     }
 
     shared_vulkan_context_provider_initialized_ = true;
   }
   return shared_vulkan_context_provider_;
 }
 
 }  // namespace content