Make cc::Display not own its BeginFrameSource

content/browser/compositor/gpu_process_transport_factory.cc

Index: content/browser/compositor/gpu_process_transport_factory.cc
diff --git a/content/browser/compositor/gpu_process_transport_factory.cc b/content/browser/compositor/gpu_process_transport_factory.cc
index 6e94f4867cd31d5f7bed294e0892d3544e709427..7dd8df2dad6f1676c7600cb2a20ee1169aa1b69c 100644
--- a/content/browser/compositor/gpu_process_transport_factory.cc
+++ b/content/browser/compositor/gpu_process_transport_factory.cc
@@ -165,7 +165,7 @@ namespace content {
 struct GpuProcessTransportFactory::PerCompositorData {
   gpu::SurfaceHandle surface_handle = gpu::kNullSurfaceHandle;
   BrowserCompositorOutputSurface* display_output_surface = nullptr;
-  cc::SyntheticBeginFrameSource* begin_frame_source = nullptr;
+  std::unique_ptr<cc::SyntheticBeginFrameSource> begin_frame_source;
   ReflectorImpl* reflector = nullptr;
   std::unique_ptr<cc::Display> display;
   bool output_is_secure = false;
@@ -439,13 +439,12 @@ void GpuProcessTransportFactory::EstablishedGpuChannel(
     }
   }
 
-  std::unique_ptr<cc::SyntheticBeginFrameSource> begin_frame_source;
   if (!compositor->GetRendererSettings().disable_display_vsync) {
-    begin_frame_source.reset(new cc::DelayBasedBeginFrameSource(
+    data->begin_frame_source.reset(new cc::DelayBasedBeginFrameSource(

[danakj, 2016/08/30 01:10:56]

I don't think you should put this into |data| until you have put the Display
into it. The old Display will still be in |data| pointing ot the old bfs. This
is the things-get-hairy part I guess

         base::MakeUnique<cc::DelayBasedTimeSource>(
             compositor->task_runner().get())));
   } else {
-    begin_frame_source.reset(new cc::BackToBackBeginFrameSource(
+    data->begin_frame_source.reset(new cc::BackToBackBeginFrameSource(
         base::MakeUnique<cc::DelayBasedTimeSource>(
             compositor->task_runner().get())));
   }
@@ -471,7 +470,7 @@ void GpuProcessTransportFactory::EstablishedGpuChannel(
       display_output_surface =
           base::WrapUnique(new SoftwareBrowserCompositorOutputSurface(
               CreateSoftwareOutputDevice(compositor.get()),
-              compositor->vsync_manager(), begin_frame_source.get()));
+              compositor->vsync_manager(), data->begin_frame_source.get()));
     } else {
       DCHECK(context_provider);
       const auto& capabilities = context_provider->ContextCapabilities();
@@ -479,21 +478,21 @@ void GpuProcessTransportFactory::EstablishedGpuChannel(
         display_output_surface =
             base::WrapUnique(new OffscreenBrowserCompositorOutputSurface(
                 context_provider, compositor->vsync_manager(),
-                begin_frame_source.get(),
+                data->begin_frame_source.get(),
                 std::unique_ptr<display_compositor::
                                     CompositorOverlayCandidateValidator>()));
       } else if (capabilities.surfaceless) {
 #if defined(OS_MACOSX)
         display_output_surface = base::WrapUnique(new GpuOutputSurfaceMac(
             context_provider, data->surface_handle, compositor->vsync_manager(),
-            begin_frame_source.get(),
+            data->begin_frame_source.get(),
             CreateOverlayCandidateValidator(compositor->widget()),
             GetGpuMemoryBufferManager()));
 #else
         display_output_surface =
             base::WrapUnique(new GpuSurfacelessBrowserCompositorOutputSurface(
                 context_provider, data->surface_handle,
-                compositor->vsync_manager(), begin_frame_source.get(),
+                compositor->vsync_manager(), data->begin_frame_source.get(),
                 CreateOverlayCandidateValidator(compositor->widget()),
                 GL_TEXTURE_2D, GL_RGB, ui::DisplaySnapshot::PrimaryFormat(),
                 GetGpuMemoryBufferManager()));
@@ -511,13 +510,13 @@ void GpuProcessTransportFactory::EstablishedGpuChannel(
           display_output_surface =
               base::WrapUnique(new GpuBrowserCompositorOutputSurface(
                   context_provider, compositor->vsync_manager(),
-                  begin_frame_source.get(), std::move(validator)));
+                  data->begin_frame_source.get(), std::move(validator)));
         } else {
 #if defined(USE_AURA)
           display_output_surface =
               base::WrapUnique(new MusBrowserCompositorOutputSurface(
                   compositor->window(), context_provider,
-                  compositor->vsync_manager(), begin_frame_source.get(),
+                  compositor->vsync_manager(), data->begin_frame_source.get(),
                   std::move(validator)));
 #else
           NOTREACHED();
@@ -528,7 +527,6 @@ void GpuProcessTransportFactory::EstablishedGpuChannel(
   }
 
   data->display_output_surface = display_output_surface.get();
-  data->begin_frame_source = begin_frame_source.get();
   if (data->reflector)
     data->reflector->OnSourceSurfaceReady(data->display_output_surface);
 
@@ -538,14 +536,13 @@ void GpuProcessTransportFactory::EstablishedGpuChannel(
 #endif
 
   std::unique_ptr<cc::DisplayScheduler> scheduler(new cc::DisplayScheduler(
-      begin_frame_source.get(), compositor->task_runner().get(),
+      data->begin_frame_source.get(), compositor->task_runner().get(),
       display_output_surface->capabilities().max_frames_pending));
 
   // The Display owns and uses the |display_output_surface| created above.
   data->display = base::MakeUnique<cc::Display>(

[danakj, 2016/08/30 01:10:56]

So just insert it into |data| after this, with a comment?

-      HostSharedBitmapManager::current(),
-      GetGpuMemoryBufferManager(),
-      compositor->GetRendererSettings(), std::move(begin_frame_source),
+      HostSharedBitmapManager::current(), GetGpuMemoryBufferManager(),
+      compositor->GetRendererSettings(), data->begin_frame_source.get(),
       std::move(display_output_surface), std::move(scheduler),
       base::MakeUnique<cc::TextureMailboxDeleter>(
           compositor->task_runner().get()));